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Several factors influence the energy production of photovoltaic (PV) installations. The widely used ground albedo value of 0.2 in utilizing the PV system modelling; a PV array should be angled at the proper angle to optimize the system's performance. Most designers do not consider albedo to get the optimum tilted angle. This study aims to improve previous research that applied a 31°optimum tilt angle for a stand-alone PV system with an albedo value of 0.7, located at Technical College/Al-Mussaib (TCM) in the Babylon Governorate, Iraq. The improvement will be taking advantage of albedo to get the maximum amount of irradiation reached PV panel by increasing the module area and then testing the PV system by increasing the tilt angle until reaching a maximum value of, a global incident in the collector plane, and effective irradiation on collectors and energy on collectors. Using PV syst. and software Perez module in simulation, the results show that the optimum tilt angle at this location with albedo 0.7 will be 38o instead of 31o. [ABSTRACT FROM AUTHOR]

Wireless power transmission (WPT) revolutionizes convenience by eliminating physical connections, enabling seamless charging for various devices. WPT faces challenges related to efficiency loss over distance, as energy transmission weakens with increased separation between transmitter and receiver. This paper aims to design and practically implement a WPT-based magnetic resonator coupling (MRC) technique to transfer energy from a transmitter coil to a receiver coil for supplying temperature and humidity environmental sensors by power using a zero voltage switching (ZVS) model. The system comprises three main circuits: receiver, transmitter, and monitoring environment. The transmitter circuit operates at a frequency of 17 kHz using the ZVS model. The receiver and transmitter coils are hand-twisted and made of 15 American Wire Gauges (AWG). Built-in environmental circuitry with a DHT11 sensor and Arduino Uno microcontroller makes it easy to monitor temperature and humidity under environmental conditions. Different impedance loads of 50, 100, 150, and 200 ohms were tested in the system at 1 and 10 cm distances between the receiver and transmitter coils. The results have shown that the system worked fairly when using 50-ohm resistors spaced between 1 and 4 cm between the transmitter and receiver coils, providing a voltage of over 4 volts and a current of over 70 mA. As a result, these parameters enable suitable environment monitoring circuits comprising the Arduino Uno microcontroller and the DHT11 sensor. Furthermore, the system attained a notable efficiency of 95% based on real measurements when the distance between the two coils was 1 cm and the resistive load value was 50 ohms. Moreover, this system shows exceptional performance compared to previous related research and shows notable improvement. [ABSTRACT FROM AUTHOR]

This study aims to design and build a 2-dimensional standing wave generator system using the Chladni plate principle. This system uses a circular membrane whose edges are clamped and several tension sensors are attached. For the vibration source, a DDS AD9850 sine signal generator is used which is placed in the center of the membrane. Salt is sprinkled on the surface of the membrane to give a visual effect of the standing waves that form on the membrane. This system is tested by providing continuous frequency so that a Chladni pattern is formed. It was found that the Chladni pattern occurred only at certain frequencies and the number of the frequency point increased with increasing membrane tension. [ABSTRACT FROM AUTHOR]

The effectiveness of Naive Bayes in conjunction with and without feature removal will be investigated using an IDS that generates a unique IDS by using backward feature deletion. The intrusion detection system was tested using the NSL-KDD Dataset. 38 sources, or 19 samples from each category, provided the data. We chose the sample size with an 80% power in mind. We ran our statistical analysis using the SPSS program. An independent sample T test with a p-value larger than 0.05 and a significance level of 0.692 was performed on the two groups. There will be a substantial association between them if p<0.05. When compared with and without feature reduction, the Innovative Naive Bayes Intrusion Detection System has an average accuracy of 0.7495 and 0.7432. There is no statistically significant difference between the two intrusion detection approaches, and the new approach that combines backward feature reduction with Naive Bayes works just as well. [ABSTRACT FROM AUTHOR]

The rapid development of technology has made it possible to improve aquaculture production through intelligent aquaculture. Intelligent aquaculture utilizes modern technologies to control aquaculture production remotely. The usability of intelligent aquaculture system is important as it helps users to fulfil their goals by using the system. This study aims to evaluate the usability of an intelligent aquaculture system by performance testing and post-test questionnaires which include System Usability Scale (SUS) and User Experience Questionnaire (UEQ). The result of this study shows the SUS score of the system is 52.25 which indicates improvements are needed to increase the usability of the system. The UEQ score shows that dependability, motivation, and novelty aspects of the system were perceived well by the users. On the other side, attractiveness, efficiency, and perspicuity aspect of the system must be improved to provide better user experience. To improve the usability of the system, it is recommended to 1) provide clearer button with an appropriate color, shape, and button name, and 2) display the name and icon of each water quality parameter on the parameter setting page. [ABSTRACT FROM AUTHOR]

The integration of renewable energy sources with advanced power grid technologies has raised concerns over electricity quality. The use of machine learning techniques enables the assessment of power quality data analysis for the purposes of identifying and mitigating disturbances. This study presents a novel approach to power quality analysis in various power systems, using machine learning algorithms. The proposed methodology involves the processing and analysis of real-time power quality data obtained from various appliances. This data is extracted using a power data collection system equipped with sensors. Subsequently, machine learning techniques and algorithms are employed to identify and classify voltage and current harmonics, as well as transients. The system uses machine learning techniques to identify, classify, and predict power quality issues by using historical data. [ABSTRACT FROM AUTHOR]

Generator coherency identification is an important step that needs to be taken in the case of a fault to enable durable islanding that could prevent a cascading blackout. Coherent generators are generally identified using the behaviour of rotor angles of the generators. Machine learning techniques have been implemented to tackle this problem. However, these techniques can be configured in different variations This research aims to implement a fine-tuned machine learning technique into the problem of generator coherency identification, to determine coherent generator groups with extreme accuracy. For this purpose, SVM was chosen as the machine learning technique to be implemented in this research, and was fine-tuned to yield the most accurate results for this problem. Data was collected in the form of rotor angles using a simulation of the IEEE 39-bus test power system in DIgSILENT PowerFactory. Based on the results obtained, SVM proved to be accurate in the primary performance metric RMSE, with a value of 0.077. Furthermore, in the secondary performance metric, R2, the value was extremely high at 0.98. Moreover, in various tests such as with reduced input data of 1000, 500, 250 and 50 out of the original 2000, and reduced computational power of 50% and 90%, SVM was accurate, in both RMSE and R2. A third performance metric, accuracy as a percentage, was also analysed, where SVM had an accuracy of 65.7%, which was compared to an RBFNN model in the literature that had a 95.03% accuracy. However, as other performance metrics show that SVM is accurate, it can be concluded that the fine-tuned SVM is applicable for the clustering of coherent generators. [ABSTRACT FROM AUTHOR]

Generator coherency identification is an important step that needs to be taken in the case of a fault to enable durable islanding that could prevent a cascading blackout. Coherent generators are generally identified using the behaviour of rotor angles of the generators. Machine learning techniques have been implemented to tackle this problem. However, these techniques can be configured in different variations This research aims to implement a fine-tuned machine learning technique into the problem of generator coherency identification, to determine coherent generator groups with extreme accuracy. For this purpose, ANN was chosen as the machine learning technique to be implemented in this research and was fine-tuned to yield the most accurate results for this problem. Data was collected in the form of rotor angles using a simulation of the IEEE 39-bus test power system in DIgSILENT PowerFactory. Based on the results obtained, ANN proved to be moderately accurate in the primary performance metric RMSE, with a value of 0.345. However, in the secondary performance metric, R2, the value was high at 0.95. Moreover, in various tests such as with reduced input data of 1000, 500, 250 and 50 out of the original 2000, and reduced computational power of 50% and 90%, ANN was accurate, in both RMSE and R2. A third performance metric, accuracy as a percentage, was also analysed, where ANN had an accuracy of 89.9%, which was compared to an RBFNN model in the literature that had a 95.03% accuracy. This concludes that the fine-tuned ANN is applicable for the clustering of coherent generators. [ABSTRACT FROM AUTHOR]

Generator coherency identification is an important step that needs to be taken in the case of a fault to enable durable islanding that could prevent a cascading blackout. Coherent generators are generally identified using the behaviour of rotor angles of the generators. Deep learning has been an up-and-coming technique to solve complex problems with supreme accuracy. This research aims to implement deep learning into the problem of generator coherency identification, to determine coherent generator groups with extreme accuracy. For this purpose, LSTM was chosen as the deep learning technique to be implemented in this research and was fine-tuned to yield the most accurate results for this problem. Data was collected in the form of rotor angles using a simulation of the IEEE 39-bus test power system in DIgSILENT PowerFactory. Based on the results obtained, LSTM proved to be extremely accurate in the primary performance metric RMSE, with the lowest value of 0.03. However, in the secondary performance metric, R2, the value was lower at only around 0.81. However, in various tests such as with reduced input data of 1000, 500, 250 and 50 out of the original 2000, and reduced computational power of 50% and 90%, LSTM reigned accurate, in both RMSE and R2. A third performance metric, accuracy as a percentage, was also analysed, where LSTM had an accuracy of 95.7%, which was compared to an ANN model in the literature that had a 95.03% accuracy. This concludes that LSTM is applicable for the clustering of coherent generators. All in all, deep learning was able to yield more accurate results compared to traditionally used machine learning techniques such as ANN in literature. [ABSTRACT FROM AUTHOR]

Based on cases of traffic accidents due to damaged roads that continue to occur every year. Efforts are needed to overcome these problems. Many researchers have made innovations related to road damage detection. Several methods are used to detect road damage, hovewer it need to implement in real time because road damage location needs to detect. In this paper, real time road damage detection is proposed. This system consist of camera, Nvidia Jetson Nano, GPS sensor. The camera as a road image capture which is then processed by the Nvidia Jetson Nano. The data is processed using the Tensorflow Object Detection framework with lite SSD as trained model of transfer learning. The results of this system are detection and classification of road damage. The detection results are classified into pothole and crack. This system was equipped by GPS sensor to detect road damage location. Based on the experimental results, the detection process should ideally be carried out at a speed of 20 km/h to 30 km/h which has an average accuracy of 80%. Based on testing the entire system at, Jl. Sumpil Basuki and Jl. serayu. The detection and mapping system can run well when with F1 score 88% [ABSTRACT FROM AUTHOR]

Athletics is a combination of several types of sports which can be broadly grouped into running, throwing, jumping, and walking. There are many people that already know about this sport, however, not many students that understand about tools are used in this sport. One of the solution that we can used to introduce the equipments of athletics to beginner students is through Augmented Reality. This technology combines real objects and virtual objects based on a media marker, which runs interactively in real time. There is also integration between objects in three-dimensional form, namely virtual objects that are integrated in the real world. This research uses Game Engine Unity and Vuforia which can display 3-dimensional objects, and using Android as the basis of the system. In this paper, we present four equipments of athletic sports, likely Discuss Throw, Pole Vault, High Jump, and Relay Race. The aim of this research is to enhance students knowledge to recognize those athletic sports equipment, so that students motivation can be increased. The result of the research is an Augmented Reality-based athletics introduction application that has been tested well for the system performance using blackbox testing, and the marker performance using various conditions of its marker. [ABSTRACT FROM AUTHOR]

High-quality software tends to be expensive to develop and maintain because it is used in social infrastructures. In previous studies, a description format for requirement specifications was defined in a form that can be handled by machines, and customers were asked to describe their requirement specifications using this description format. However, a method for generating test cases from natural language documents has not been developed. We proposed a method to automatically generate test cases for system tests from requirement specifications. We applied this method to various system specifications and confirmed its usefulness. As a result, sufficient accuracy was obtained, confirming the usefulness of the proposed method. We also applied the proposed method to large-scale communication node software and clarified the specification-dependent characteristics of the proposed method. [ABSTRACT FROM AUTHOR]

Widan Technology (Widantech), which operates in the software house sector, has several clients with small to medium scale projects. A high demand project is the company profile website application. In Widantech company profile projects, role and module management are not included, so any changes to module and data access must be carried out by the Widantech programming team. The increasing number of clients requires an adaptive development model according to module additions and changes. However, lack of skills are the main obstacle in analyzing adaptive system models. Even though an adaptive system is needed to facilitate user managers to manage access rights to modules and data. This setting is very important because it relates to the security of client company information. Implementing a module and data access rights model is needed to ensure the adaptability of the company profile product being created. Setting access rights is one important component to accommodate these requirements. Module and data access rights management are implemented through the stages of collecting entities related to company profiles, observing several Widantech client company profile systems, implementing modules and data access rights, and system testing. The module and data access rights model can support the development of an adaptive company profile system for Widantech clients. [ABSTRACT FROM AUTHOR]

This paper presents the design and implementation of a tool that allows the simultaneous measurement of Isc, Voc, irradiance, ambient temperature and PV panel temperature. The data collected can be exhibited on a screen or saved to a memory card through a data logger system. The implementation steps are as follows: designing, assembling, individually testing each sensor, and testing the overall system. The performance of this tool is tested by comparing its measurement results to those of conventional measuring instruments. This tool has been proven to measure Isc, Voc, irradiance, ambient temperature and photovoltaic temperature simultaneously. Its measurement results show an average deviation of less than 2% compared to conventional measuring instruments. [ABSTRACT FROM AUTHOR]

Thermoelectric air conditioners with Solar photovoltaic are better and suitable for remote locations, particularly those with direct power source from the sun. In this study, a low-cost solar-thermoelectric air-conditioning duct has been developed and built for cooling and heating purposes in remote places where energy is still unavailable or insufficient. The thermoelectric peltier has low coefficient of performance. The goal of this research is to evaluate the performance of the thermoelectric air-conditioning to obtain optimum operation technique for the system and better COP values. The volume flow rate affects the dissipation of heat from the hot side of the thermoelectric cooler, which in turn influences the performance of the thermoelectric air conditioning system. In this work the performance of thermoelectric air-conditioning system tested for three volumetric flow rate value of (0.003, 0.005 and 0.007) m3/s. It was shown that the COP is higher in the case of 0.007 m3/s velocity with average value 0.39, which is 1.18 time greater than the 0.005 m3/s case and 1.33 time than the 0.003 m3/s. Using sufficient convection air on hot side reduce the temperature difference along the day and which leads to higher COP can be obtain which give better Performance. The exergy efficiency enhances in the case 0.007 m3/s by 41.97% from 0.005 m3/s case and 24.6% from the 0.003 m3/s case. [ABSTRACT FROM AUTHOR]

The krill herd (KH) approach is proposed in this article for tackling the dynamic economic dispatch (DED) issue with valve point loadings (VPL). The purpose of resolving the DED problem is to find the optimum feasible combinations of output powers of all committed generators within a given time period while simultaneously meeting dynamic operational constraints and satisfy the total load. With the addition of valve-points in the generator cost characteristics, the DED issue becomes an inherently non-linear and non-convex issue and the DED is going to be more complicated when losses are taken into account. KH is a swarm-inspired algorithm based on krill individual herding behaviour. KH employs two global and local tactics and these works in parallel, making KH an efficient evolutionary technique. The suggested technique was tested on DED systems with 6 and 15 units, and the findings showed that the KH is effective at solving DED issues. [ABSTRACT FROM AUTHOR]

This paper presents the quantitative analysis of market power of the Generation Companies (GENCOs) and the impact of congestion on it in the deregulated electricity market. The intensity of market power of the GENCOs has been obtained by making use of a novel Market Revenue Share (MRS) index. The MRS of a GENCO is defined as a revenue earned by it as a fraction of total market revenue of all the participating GENCOs in the deregulated electricity market during any specific time span. The MRS of GENCOs has been obtained by solving an optimal power flow problem for maximizing social welfare function subject to the non-linear operational and congestion constraints. From the present electricity market real studies, it is noticed that under congested system conditions, some costly generators can get chance to exercise market power in the deregulated environment. The effectiveness of the proposed methodology has been demonstrated on IEEE-30 bus test system. It has been observed that due to congestion, there is an increase in the value of MRS Index of some costly generators which implies that GENCOS's ability to exercise market power increases with congestion in the deregulated electricity market. [ABSTRACT FROM AUTHOR]

Minimization of the cost of generation for any utilities is crucial to ensure the utilities will be able to maintain continuous supply and their survivability. Non-optimal amount of power generated by all generating stations in a country will possibly lead to monetary loss and ineffective operation of the power system. Thus, a robust and reliable optimization technique is the prerequisite to ensuring the lowest cost of generation can be achieved. This paper proposes a hybridized optimization technique that integrates the element of evolutionary programming (EP) into the barnacle mating optimizer (BMO), termed Hybrid Evolutionary Programming-Barnacles Mating Optimization (HEBMO). HEBMO is utilized to address the convex economic dispatch in a power transmission system. Its implementation on the IEEE 30-Bus Reliability Test System (RTS) in addressing the convex ED is remarkable, through the comparison with the traditional EP and BMO. The cost of generations in chosen cases such as base case conditions, stress conditions due to real power, and reactive power increments revealed the superiority of the proposed HEBMO over EP and BMO. [ABSTRACT FROM AUTHOR]

Health is something that is very valuable and expensive for all humans. Currently, many people are not aware of the symptoms of an inguinal hernia which is a disease that most people do not understand. Hernia is a disease caused by the descent of the intestine under the lining of the abdomen into the testicles. This disease often occurs in heavy workers such as coolies, factory workers, and other heavy work. For that we need a mobile-based application that can diagnose hernia disease early and avoid worsening of the disease. One of the methods in the expert system is the method of certainty factor. After performing 15 times of expert testing using this system, the mean score of diagnostic evidence was 84% with an accuracy rate of 86.6%. [ABSTRACT FROM AUTHOR]

The performance of the brake system significantly affects the safety, handling, and dynamics of the car. This paper aims to formulate an approach and develop a detailed methodology for designing a brake system for a racing Formula Student class race car, considering the requirements of the competition regulations. To accomplish this task, design calculations were performed to determine the pressure required to stop the car and calculations confirming the operability of the developed parts. The analysis is carried out in three stages. The first step is to determine the pressure necessary to ensure the wheels are locked. The second stage selects the system parameters and structural elements that can provide the necessary pressure. The third stage is the topological optimization of structural elements, considering the conditions of the regulation and the preservation of strength characteristics. To verify the calculations of the brake system with a balancing rod as a pressure distribution mechanism, field tests were performed. During field tests of the brake system, the design of the pedal assembly was not destroyed. As a result of the work done, a methodology for designing a workable brake system and its control body was developed. [ABSTRACT FROM AUTHOR]

The distortion of scene image by the pair «infrared lens/thermo-electronic converter» is investigated. Under the assumption that on the cold scene point heat source is placed randomly in such a way, that probabilities of its appearance at any direction are independent and unformed, the expression for information capacity is obtained. It is shown, that distortion decreases amount of information, when scene signal is transformed into its thermal image. Information losses are linked with changing of cells inverse projection on the observed scene space. Formulae for area of inverse cell projections and for information losses calculation in the IR system with pincushion and barrel type distortions are obtained. The structure of the testing system has been developed, the main element of which are eight IR LEDs, placed along the edges of the scene. The uncomplicated engineering method of IR sensor quality evaluation is proposed. [ABSTRACT FROM AUTHOR]

In the edition of ISO/IEC 17025:2017, the topic of risk management in the management system of testing laboratories is becoming increasingly relevant. This edition of the standard obliges each testing laboratory to include in its management system a documented procedure that describes the actions to manage risks and opportunities. [ABSTRACT FROM AUTHOR]

The testing of different types of hydraulic elements and systems is directly related to the ability to measure several basic parameters in hydraulics, such as pressure and flow rate. Pressure can be measured relatively easily by attaching control points to measure pressure in the system by means of manometers. Measuring pressure in hydraulic systems is much easier and much cheaper than measuring flow rate in a given system. Apart from the expensive turbine hydraulic flow meters which are most commonly used in practice, the present work offers an alternative concept for flow rate measurements within the range of 0 to 25 l/min. The elements used for the system build up are given and explained. The method and the system test results are presented and analyzed. It is also made a comparison between three experiments that was made. [ABSTRACT FROM AUTHOR]

The methodology for testing the performance of virtualization systems when using different guest operating systems is discussed in this article. A cross-platform program with 14 tests was developed for performance testing. Three virtualization systems were tested: Oracle Virtual Box, VMware Workstation, and Microsoft Hyper-V. The program was tested on two different guest operating systems: Windows and Ubuntu. Testing has revealed that when the Ubuntu guest operating system is used, the performance of the virtualization systems under consideration is roughly the same. In terms of test execution speed, the VMware Workstation hypervisor outperforms other virtualization systems when running on Windows. In general, the runtime of tests on Ubuntu was significantly shorter than on Windows across all virtualization systems. The test execution time on the host operating system Windows and the guest operating system Windows were compared. Test execution time on the host is roughly twice that of the guest operating system. If the test program performs a large number of arithmetic operations, the performance hit is reduced. When the test program works intensively with memory, performance suffers significantly. This is true for all virtualization systems under consideration. [ABSTRACT FROM AUTHOR]

The research aims to design a system that cuts the cancerous area in the esophageal tissue that is often detected in late stages, using the FCM algorithm. This algorithm has achieved impressive results in determining the tumour area, which is; (sensitivity of 0.98, Accuracy of 0.95, and specificity of 0.92). The proposed system was tested on 200 images, which were downloaded from the Kaggle website. This research showed that is not possible to improve the images before using them in segmentation, due to the type of noise experienced by the data set is not uniform, because the images uploaded to the mentioned site are in JPG format (compressed images), which are losing many their features. [ABSTRACT FROM AUTHOR]

Software testing consists of reviewing software to determine whether it is functioning as expected or not. There are many testing techniques available. A tester should be able to choose the appropriate technique for each case at hand. Sometimes, testers find it difficult to test software, especially dynamic ones that describe the flow of an organization's business processes. This study focuses on testing the process flow in an information system and applying state transition diagram to test the transition between states. This research aims to determine how to properly test the business process flow of an information system using the state transition diagram and ensure the suitability of the business process flow. This stage of research begins with creating a state transition diagram based on the business process flow. Following the creation of the state transition diagram, the system will be tested. The final stage is to make changes based on the test results. The study concludes that the system, which was initially unable to handle business processes properly, has now succeeded in running precisely by the existing business processes. Tests and improvements have resulted in a system that is correct in terms of business process flow. Since state transition diagrams have proved successful in testing information systems, new guidelines for testing the transitions between states have been developed. [ABSTRACT FROM AUTHOR]

The fixed-wing UAV vehicle can fly glide and has long-range roaming capability. On the other hand, rotary-wing UAVs can fly (hover) but cannot fly during fixed-wing. Fixed-wing rides can experience deviations when turning at large turning angles when doing waypoint missions. Deviations that occur due to maneuver limitations can be overcome by combining fixed-wing UAV and rotary-wing UAV types. The LQR control stabilizes both vehicle modes by processing multiple inputs for use on multiple outputs. System testing is carried out on the path tracking to find out the system's functioning, while the results of tests that have been carried out for three waypoint points were obtained, for the WP1 point to the WP2 point, and the deviation occurred by 3 meters. Then for the movement from the WP2 point to the WP3 point, the deviation is 2.5 meters. The ride time from the start point to the finish point is 30 seconds. [ABSTRACT FROM AUTHOR]

The article is devoted to the description of methods and algorithms for ensuring the reliability of the transportation process for goods and own empty wagons by rail in terms of intelligent commercial inspection of trains and wagons using digital technologies, and primarily neural networks. It contains description of a formal recurrent model, a task decomposition tree built according to an object-oriented and method-oriented principle, a description of autodiagnostic methods: weighing, zone control, laser scanning, neural network photodiagnostics, temperature control and radio frequency control. The architecture of built system and test results are also given. [ABSTRACT FROM AUTHOR]

According to the World Health Organization, there are approximately 285 million blind people around the world. Those people faced challenges in their life, especially when reading a book. This paper is aims to test and evaluation the audio reading system (which is use to help the blind person to read the book) with new dataset which consist of 161 image, 8 font size, mono and color image, and different views. The system is test and discussion from the aspects: accurate, Font size and type, and more reliable. According to the results (on our dataset (image type, 161 images)), the characteristics of the system is efficient and accurate real time system with cloud computing and the accuracy increase while the font size increase, whereas the accuracy of font size 30 is 100% and of 12 is 80%. [ABSTRACT FROM AUTHOR]

Circular thin plates are using in a wide range of engineering applications like roof and floor of building, deck slab of bridge, water tanks, turbine disks etc. Despite that, few experimental studies have been conducted to examine the behavior of a thin circular plate under uniformly distributed loads. The present study investigates the failure behavior of uniformly loaded clamped circular thin plates experimentally. The tests are conducting with a pressure system specially built for this work. It was developed to measure the maximum deflection of the circular plate under uniform internal hydrostatic pressure. Numerical and experimental results were compared and showed a good correlation for all plates investigated. The failure mechanism is discussed based on the results of numerical calculations and the results of a scanning electronic microscope (SEM). The results observed in this study show a good understanding of the problems related to different internal pressure values. [ABSTRACT FROM AUTHOR]