bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of positive emotion in children mobile learning application
Authors: Gasah Magrizef , Baharum Aslina , Hidayah Mat Zain Nurul , Halamy Suhaida , Hanapi Rozita , Aizuddin Mat Noor Noorsidi
Published: March 2020

This paper presents the evaluation of positive emotion in children's mobile learning applications. The mobile learning application is a teaching aid that can help students to self-study and increase the students’ interest in learning especially children. This paper will discuss how mobile learning application affects the children interest in school. The evaluation method implemented to evaluate the rate of positive emotion elicited by the children using mobile learning applications was a mixed method of qualitative and quantitative methods. Since emotion can be either negative or positive, the identification of a proper method or perspective was required to prove that positive emotion was really elicited. Next, the data was collected through the children’s assessment score, Electroencephalograms (EEG) device, Emotion identification using micro-expression (facial expression), Kort Scale and interview to confirm the positive emotion felt by the students. The result shows that all five perspectives or methods have shown that positive emotion is produced. It is found that the Mobile learning application can really trigger the children’s positive emotions.
Grey wolf optimizer for identification of liquid slosh behavior using continuous-time hammerstein model
Authors: Ahmad Mohd Ashraf , Musa Zulkifli , Helmi Suid Mohd , Zaidi Mohd Tumari Mohd
Published: March 2020

This paper presents the identification of liquid slosh plant using the Hammerstein model based on Grey Wolf Optimizer (GWO) method. A remote car that carrying a container of liquid is considered as the liquid slosh experimental rig. In contrast to other research works, this paper consider a piece-wise affine function in the nonlinear function of the Hammerstein model, which is more generalized function. Moreover, a continuous-time transfer function is utilized in the Hammerstein model, which is more suitable to represent a real system. The GWO method is used to tune both coefficients in the nonlinear function and transfer function of the Hammerstein model such that the error between the identified output and the real experimental output is minimized. The effectiveness of the proposed framework is assessed in terms of the convergence curve response, output response, and the stability of the identified model through the bode plot and pole zero map. The results show that the GWO based method is able to produce a Hammerstein model that yields identified output response close to the real experimental slosh output.
Modelling and simulation of online partial discharge measurement for medium voltage power cable
Authors: Abdullah A. Z. , Isa M. , N. K. H. Rohani M. , Hamid H. A. , Amlus M. H. , Azizan N.
Published: March 2020

This paper presents the modelling of the online partial discharge (PD) measurement of the medium voltage (MV) power cable. Recently, PD monitoring trends are rapidly increasing due to high demand on reliable systems. Degradation are mainly due to the presence of PD in the high voltage power equipment used. PD measurement is therefore a highly recommended task to early detection of the degradation insulation for high voltage (HV) equipment in order to avoid breakdowns. Real network modelling is necessary to improvise system design in order to find the efficiency in a real power system network. In this paper, modelling focuses on a real distribution network by applying Rogowski coil (RC) as a detection sensor to trigger PD activity. The simulation is performed to determine the functionality and reliability of the system with the RC application in the network. The analysis is performed in the ATP-EMTP and MATLAB Simulink software environments. In addition, this paper contributed to justify the approach of a simplified PD sensor and measurement system. This PD measurement system provides a complete solution in the context of condition-oriented monitoring for the ability to apply the RC to trigger PD activity in the power distribution network.
Reliability study on the adaptation of Dijkstra’s algorithm for gateway KLIA2 indoor navigation
Authors: A. F. A. Samah K. , Sharip A. A. , Musirin I. , Sabri N. , Salleh M. H.
Published: March 2020

This paper describes a reliability study on the adaptation of Dijkstra’s Algorithm (DA) in the indoor environment for navigation purposes. Gateway KLIA2 located at Sepang, Selangor, Malaysia has been chosen as the area for case study. Gateway KLIA2 is divided into 4 levels but this research focused on Level 2 only that consists of 129 shop lots. A survey conducted towards 68 public respondents before the adaptation and most of them responded that they are not aware of the surrounding of KLIA2 and are facing difficulties in finding the information or location of certain places inside the building. DA was chosen because it helps the users to navigate using the shortest path to destination. It is proven that through the adaptation of DA, we are able to provide the shortest distance for indoor navigation from current location to the destination location. G-INS is reliable based on the functionality and reliability testing conducted towards 15 users with the distance reduction of 47% t-test result of 0.01303 (p0.05), indicates the system is accepted
Missing data exploration in air quality data set using R-package data visualisation tools
Authors: Ghazali Shamihah Muhammad , Shaadan Norshahida , Idrus Zainura
Published: March 2020

Missing values often occur in many data sets of various research areas. This has been recognized as data quality problem because missing values could affect the performance of analysis results. To overcome the problem, the incomplete data set need to be treated or replaced using imputation method. Thus, exploring missing values pattern must be conducted beforehand to determine a suitable method. This paper discusses on the application of data visualisation as a smart technique for missing data exploration aiming to increase understanding on missing data behaviour which include missing data mechanism (MCAR, MAR and MNAR), distribution pattern of missingness in terms of percentage as well as the gap size. This paper presents the application of several data visualisation tools from five R-packges such as visdat, VIM, ggplot2, Amelia and UpSetR for data missingness exploration.  For an illustration, based on an air quality data set in Malaysia, several graphics were produced and discussed to illustrate the contribution of the visualisation tools in providing input and the insight on the pattern of data missingness. Based on the results, it is shown that missing values in air quality data set of the chosen sites in Malaysia behave as missing at random (MAR) with small percentage of missingness  and do contain long gap size of  missingness.
Mel-log energies analysis of authentic audible intrusion activities in a Malaysian forest
Authors: Md Afendi Amirul Sadikin , Yusoff Marina , Omar Megawati
Published: March 2020

Wildlife has been endangered due to illegal activities.  This requires more effective surveillance measures.  Felling timber and poaching are regular illegal activities but challenging to detect.  Hence authorities should resort to modern technologies such as employing autonoumous surveillance to stop them.  The Malaysian forest audio data were recorded to lay a foundation in initiating a cheaper and practical approach.  Hence this paper reports the collection, processing and analysis of audio data in preparation to develop an autonomous sound event detection system.  The recording was an emulation of possible illegal activities in a reserved forest.  Sounds of chainsaw and hand hatchet cutting tree trunks were taken.  It was found that there was a distinct pattern in the Mel-log energies audio feature of the sound, which could be used to identify illegal activities.  Thus, it is believed that a detection through audio is a possible approach to be employed as one of the methods to stop illegal activities in the tropical reserve forests like those in Malaysia.
A prosthetic limb managed by sensors-based electronic system: Experimental results on amputees
Authors: Gaetani F. , De Fazio R. , Zappatore G. A. , Visconti P.
Published: March 2020

Taking the advantages offered by smart high-performance electronic devices, transradial prosthesis for upper-limb amputees was developed and tested. It is equipped with sensing devices and actuators allowing hand movements; myoelectric signals are detected by Myo armband with 8 ElectroMyoGraphic (EMG) electrodes, a 9-axis Inertial Measurement Unit (IMU) and Bluetooth Low Energy (BLE) module. All data are received through HM-11 BLE transceiver by Arduino board which processes them and drives actuators. Raspberry Pi board controls a touchscreen display, providing user a feedback related to prosthesis functioning and sends EMG and IMU data, gathered via the armband, to cloud platform thus allowing orthopedic during rehabilitation period, to monitor users’ improvements in real time. A GUI software integrating a machine learning algorithm was implemented for recognizing flexion/extension/rest gestures of user fingers. The algorithm performances were tested on 9 male subjects (8 able-bodied and 1 subject affected by upper-limb amelia), demonstrating high accuracy and fast responses.
Formulations for joint order picking problems in low-level picker-to-part systems
Authors: Cano Jose Alejandro
Published: March 2020

This article introduces several mathematical formulations for the joint order picking problem (JOPP) in low-level picker-to-part warehousing systems. In order to represent real warehousing environments, the proposed models minimize performance measures such as travel distance, travel time and tardiness, considering multi-block warehouses, due dates, and multiple pickers. The number of constraints and decision variables required for each proposed model is calculated, demonstrating the complexity of solving medium and long-sized problems in reasonable computing time using exact methods. The proposed models can be followed as a reference for new solution methods that yield efficient and fast solutions.
Introduction to inmarsat broadband global area network for mobile backbone networks
Authors: Ilcev Stojce Dimov
Published: March 2020

In this paper is introduced the Inmarsat Global Area Network (GAN) as backbone to mobile networks. At the end of 2005 Inmarsat launched its BGAN service as the first high speed wireless data solutions with voice available on a global basis. The service is accessed through a portable, broadband satellite transceiver with antenna easy to carry as a laptop. The BGAN network consists constellation of Geostationary Earth Orbit (GEO) I-4 and I-5 satellites with an optimized ground network, which interconnects variety of terrestrial infrastructures at local BGAN users. This system employs bandwidth efficient modulation and coding techniques, capable of supporting variable bit-rate services and QoS depending on the needs of the application. The BGAN system is satellite component of 3G IMT-2000, specially the Universal Mobile Telecommunications Service (UMTS) standards. It will provide a near-global coverage overlay for the terrestrial networks, giving users service availability beyond the reach of terrestrial IMT-2000 networks. A range of supported terminals, personal devices, portable and mobile units linked with onboard entertainment, communications systems to remote base stations for civilian and military applications and SCADA or M2M are discussed.
Security performance analysis for power domain NOMA employing in cognitive radio networks
Authors: Hoang Thi-Anh , Le Chi-Bao , Do Dinh-Thuan
Published: March 2020

The power domain non-orthogonal multiple access (NOMA) technique introduces one of the fundamental characteristics and it exhibits the possibility of users to decode the messages of the other paired users on the same resources. In cognitive radio inspired NOMA (CR-NOMA), the base station (BS) has to serve untrusted users or users with different security clearance. This phenomenon raises a security threat particularly in such CR-NOMA. This paper develops a tractable analysis framework to evaluate the security performance of cooperative non-orthogonal multiple access (NOMA) in cognitive networks, where relay is able to serve two far NOMA users in the presence of external eavesdropper. In particular, we study the secrecy outage probability in a two-user NOMA system. This situation happens in practical the BS is pairing a legitimate user with another untrusted user. Main reason is that the non-uniform distribution in terms of trusted and untrusted users in the cell. By performing numerical results demonstrate the performance improvements of the proposed NOMA scheme in comparison to that of several situations in terms of different parameters. Furthermore, the security performance of NOMA is shown to verify the derived expressions.
Generalized sub band analysis and signal synthesis
Authors: Zhilyakov Evgeny G. , Belov Sergei P. , Oleinik Ivan I. , Babarinov Sergei L. , Trubitsyna Diana I.
Published: March 2020

Currently, one of the main approaches used in analyzing properties and synthesis of signals in various classes is the subband methodology, which is carried out from the position of Fourier transform of signal samples (frequency representations) into subbands of the transform definition domain  (transformants). In this case, the main tool, which is widely used for subband analysis (including wavelet analysis), is usage of bandpass filters (mainly those with finite impulse response or FIR filters). The present paper  introduces the basics of building a theory forsubband analysis / signal  synthesis for various classes, and using transformations based on any  orthonormal basis with weight. This proposed approach is based on the  concept of Euclidean signal norm square fraction in a given subband of the transformant definition domain. It is shown that the basis for mathematical apparatus of subband analysis is a new class of matrices, called subband ones. Some eigenvalue properties of these matrices are established, and the problem of optimal selection for additive signal components is formulated and solved
On the evaluation of noise immunity of different classes of wideband signals
Authors: Zhilyakov Evgeny G. , Belov Sergei P. , Belov Andrei S. , Belov Alexander S. , Rachinsky Sergey A.
Published: March 2020

The current stage of the development of the society is characterized by a continuous increase in remote interaction between subscribers and user requests for various types of multiservice services, with the required quality regardless of their location. This is mainly implemented on the basis of wireless communication systems (SBS) at the current time. A large number of various SBSs existing at the present leads to an increase in the level of various types of interference, which makes it necessary to increase the noise immunity of these systems. To improve the reliability of receiving information in the conditions of various types of interference, as is known, it is necessary to implement the information exchange by using channel signals with a large base, which primarily depends on the bandwidth they occupy. In this regard, in the present article, a comparative assessment of the noise immunity is carried out based on the obtained quantitative values of frequency characteristics of a number of modern classes of broadband channel signals, including a new class of broadband channel signals, and the use of eigenvectors of sub-band matrices.
Application of fuzzy logic in order to plan and create software for converting sound to text
Authors: Hasanzadeh Hiwa , Majidpour Jafar
Published: March 2020

The challenge of software in the field of converting sound to text is that some words have different meanings. In these situations, the functions of each one is distinguished by the use of fuzzy logic and division of the working part of the work. In this regard, the words must first be classified according to the specialized discipline. In the second place, the principles of writing should be maintained. In this regard, the points and commands and the alignment of the sentence are all items that should be considered in the software. The next item is the volume and speed of word processing and the lack of restrictions in the number of languages used. But the time problem is very important. In this regard, the use of existing codes and the optimization and remedy of the problems is a suitable method.In this research, some issues including security and maintenance of software proprietary rights, and the speed of converting sound to text and reducing noise and optimal performance of software to convert audio to text based on software method and the principles of fuzzy logic and neural network were investigated. Results showed improvement algorithm Analytical and results outcomes.
Determination of transient thermal characteristics for thermal electric behavioral models of integrated circuits
Authors: Yu Drakin A. , A. Potapov L. , N. Shkolin A.
Published: March 2020

In the current study, it was tried to describe a method for determining thermal characteristics of integrated micro-circuits to identify thermal parameters of multidisciplinary (thermal-electric) behavioral models. The problem is solved on the example of high-frequency pulse voltage converters. A solution was proposed to refine the minimum structure of the thermoelectric model based on an iterative least squares method using the Levenberg-Marquardt  algorithm, as well as a graph of the spectral den-sity of time constants. This made it possible to reduce the influence of the filtering factor in the  deconvolution operation when building a thermal model using the structural function of the thermal characteristic transition. Also, the results obtained can be used to build integrated circuits (IC) behavioral models, taking into account the thermal processes occurring in them.
Application of phase-metric compensation method for geoelectric control of near-surface geodynamic processes
Authors: R. Kuzichkin O. , S. Vasilyev G. , V. Grecheneva A. , V. Mikhaleva E. , D. Baknin M. , I. Surzhik D.
Published: March 2020

This work is devoted to the application of the compensation method of geoelectric control using the field phase characteristics for the detection and localization of geodynamic processes on example of the development of the karst-suffusion cavity. High noise immunity of the phase-metric registration method of geoelectric signals in comparison with amplitude parameters of the anomalous components of electromagnetic field, usually used to analyze the results of observations, is noted. A formalized approach to the use of phase characteristics of the field for the interpretation of monitoring data and associated problem of geodynamic processes localization is developed. In the framework of this approach, the section parameters are proposed to determine by the minimum sum of weighted mean square interpretation error and regularizing functional containing a priori information about the geoelectric section. To check localization possibility of the spherical karst-suffusion cavity, simulation of the amplitude and phase anomalous components of the field potential, as well as the standard error of heterogeneity localization, when moving the sphere center along the installation profile, is carried out. Simulation has shown a good potential differentiation from the inhomogeneity position, the highest accuracy of localization is achieved with combined use of amplitude and phase field components in the problem of inhomogeneity localization.
Negative refraction metamaterial with low loss property at millimeter wave spectrum
Authors: A. F. Esmail B. , A. Majid H. , Saparudin F. A. , Jusoh M. , Y. Ashyap A. , Al-Fadhali Najib , K. A. Rahim M.
Published: March 2020

The design of the millimeter-wave (MMW) metamaterials (MMs) unit cell operates at 28 GHz is presented and numerically investigated. The proposed structure composed of a modified split ring resonator (MSRR) printed on both sides of the substrate layer. Popular MM structures such as S-shape, G-shape, and Ω-shape are adjusted to operate at the 28 GHz for comparison purpose. MSRR achieves a wide bandwidth of 1.1 GHz in comparison with its counterparts at the resonance frequency. Moreover, the proposed structure presents very low losses by providing the highest transmission coefficient, S21, at the corresponding frequency region. The radiation loss is substantially suppressed and the negativity of the constitutive parameters of the proposed MM structure is maintained. By applying the principle of the electromagnetically induced transparency (EIT) phenomenon, the MSRR unit cell induces opposite currents on both sides of the substrate which leads to canceling out the scattering fields and suppresses the radiation loss. The constitutive parameters of the MM structures are retrieved using well known retrieval algorithm. The proposed structure can be used to enhance the performance of fifth generation (5G) antenna such as the gain and bandwidth.
Dye pH variation on blueberry anthocyanin based dye sensitized solar cell
Authors: Abidin Zainul , Maulana Eka , Mudjirahardjo Panca , Fadillah M. Ivan
Published: March 2020

Anthocyanin is a type of natural pigment that gives color to plants and can be used to absorb visible light with wavelength of 400-600 nm. The absorption ability is very useful for dye in designing dye sensitized solar cell (DSSC). The anthocyanin can be extracted from blueberry and has unique characteristic of high stability when it reaches low pH. In this paper, design of DSSC with dye made of blueberry anthocyanin and its performance related to pH variation is presented. The performance was evaluated experimentally according to output voltage and current generated by 4 fabricated samples (pH of 1.5, 2, 2.6, 4.4) from A.M 1.5 sunlight and 10-watt LED. Experiment results show that for both light sources, dye with pH of 1.5 has the highest output voltage and current among the others. Since the output voltage and current are very small, the exsisting design of DSSC is suitable to be developed for optical sensor.
Decision support system for determining chili land using weighted product method
Authors: Ramadiani Ramadiani , Ramadhani Bayu , Arifin Zainal , Jundillah Muhammad Labib , Azainil Azainil
Published: March 2020

Chili is one of the most consumed food commodities in Indonesia. Thus, chili is very influential to the economic, also inflation and deflation of an area. In order for the needs of chili to be fulfilled and to be able to export, the production must be increased with one consideration being the selection of the right land. The right land must meet the criteria agreed upon by experts, there is land height, soil pH, nutrient value and ambient temperature. This research aims to create a system to support the decision of chili crop land selection using the weighted product method. By entering land data according to the criteria, the user can easily find out which land has the potential to have a higher suitability for chili plants. The result of this system is in the form of land ranking that can help users decide which land to use for chili cultivation.
Teacher and student readiness using E-learning and M-learning
Authors: Ramadiani Ramadiani , Azainil Azainil , Hidayanto Achmad Nizar , Khairina Dyna Marissa , Jundillah Muhammad Labib
Published: March 2020

This research is about the readiness of teachers and students to develop E-learning and M-learning for the learning process. Before developing and implementing an E-learning and M-learning system, it is important to ensure the user's readiness for the technology. Users' perceptions will affect their willingness and readiness to use the system. This study aims to investigate the teachers and students perceptions about E-learning and M-learning, ensuring their readiness to involve in developing online learning process. The study was conducted by survey methods, questionnaires and direct interviews with prospective users in the schools, students, teachers and principals. Research respondents were from Junior High School and Senior High Schools in Samarinda. The questionnaires will be carried out in two stages, before and after the development of E-learning and M-learning systems. The findings obtained from this study indicate that research partner schools are ready and able to participate in developing E-learning and M-learning systems.
Hybrid optical communications for supporting the Palapa Ring network
Authors: Darusalam Ucuk , Zulkifli Fitri Yuli , Priambodo Purnomo Sidi , Rahardjo Eko Tjipto
Published: March 2020

In order to connecting villages in rural area with a city, a hybrid optical communication is proposed. The Optical fiber communications that are implemented as a backbone on the Palapa Ring network has an opportunity to be expanded to reach rural area through the implementation of free-space optical communications (FSO) as the optical relaying networks (ORN). The major problem of FSO as the ORN is turbulence effects induce an optical propagation. In this research, FSO as the ORN implements novel technique to improve the performance of hybrid FSO where the amplification of signal is produced through serial configuration of optical amplifiers in cascaded meanwhile to reduce the noise in the end of receiver, optical band pass filter is implemented. The simulation of hybrid FSO is performed in Optisystem 7.0 where ORN is implemented in two nodes. The length of optical fiber connection to FSO is set to be constant at 75 km. The range of optical propagation in FSO is set at 1–9.4 m. The results of simulation show that at the range of 1–8 Km of optical propagation under atmospheric turbulence, range values for SNR and BER are achieved at 46.23–26.61 dB and 6.7x10-17–1.5x10-6, respectively.
Deep learning based facial expressions recognition system for assisting visually impaired persons
Authors: Kusuma Hendra , Attamimi Muhammad , Fahrudin Hasby
Published: March 2020

In general, a good interaction including communication can be achieved when verbal and non-verbal information such as body movements, gestures, facial expressions, can be processed in two directions between the speaker and listener. Especially the facial expression is one of the indicators of the inner state of the speaker and/or the listener during the communication. Therefore, recognizing the facial expressions is necessary and becomes the important ability in communication. Such ability will be a challenge for the visually impaired persons. This fact motivated us to develop a facial recognition system. Our system is based on deep learning algorithm. We implemented the proposed system on a wearable device which enables the visually impaired persons to recognize facial expressions during the communication. We have conducted several experiments involving the visually impaired persons to validate our proposed system and the promising results were achieved.
MRI brain tumor segmentation: A forthright image processing approach
Authors: Khalid Noor Elaiza Abd , Ismail Muhammad Firdaus , Manaf Muhammad Azri AB , Fadzil Ahmad Firdaus Ahmad , Ibrahim Shafaf
Published: March 2020

Brain tumor is a collection of cells that grow in an abnormal and uncontrollable way. It may affect the regular function of the brain since it grows inside the skull region. As a brain tumor can be possibly led to cancer, early detection in Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scanned images are crucial. Thus, this paper proposed a forthright image processing approach towards detection and localization of brain tumor region The approach consists of a few stages such as pre-processing, edge detection and segmentation. The pre-processing stage converts the original image into a greyscale image, and noise removal if necessary. Next, the image is enhanced using image enhancement techniques. It is then followed by edge detection using Sobel and Canny algorithms. Finally, the segmentation is applied to highlight the tumor with morphological operations towards the affected region in the MRI images. The in-depth analysis is measured using a confusion matrix. From the results, it signifies that the proposed approach is capable to provide decent segmentation of brain tumor from various MRI brain images.
City i-Tick: The android based mobile application for students’ attendance at a university
Authors: Alimin S. R. , H. Abdul Hamid N. , Nasruddin Z. A.
Published: March 2020

This paper presents City i-Tick, the android based mobile application for students’ attendance at a university. In this study, we developed mobile application for lecturers to take students’ attendance in City University, Petaling Jaya. Managing students’ attendance during lecture periods has become a difficult challenge. The research objectives for this study are to identify user requirement for City i-Tick, to design and develop City i-Tick, and to demonstrate the prototype of City i-Tick. The study is a narrative participatory design and exploits Design Thinking as the research methodology. City i-Tick was successfully validated by 14 lecturers and System Usability Scale (SUS) was used to determine the findings of the study. We found that City i-Tick is effective for lecturers in taking attendance because it is easy to use, easy to learn, and the users feel confident when using this application.
D2D communication for spectral efficiency improvement and interference reduction: A survey
Authors: Alquhali Abdullah H. , Roslee Mardeni , Y. Alias Mohamad , Mohamed Khalid S.
Published: March 2020

Device-to-device (D2D) communication system plays an extremely important role in fulfilling the demands of fourth generation (4G) and fifth generation (5G) technologies. 4G technology cannot meet high data demands. The D2D communication system is believed to provide major improvements in resource usage, energy efficiency, and overall throughput, which are the main demands for the 5G network. Some of the main issues in the D2D communication system involve spectrum efficiency and interference. Although many studies have been conducted on spectrum efficiency improvement and interference reduction, the issues still remain. A study should be conducted to obtain a better understanding of the D2D communication system and to develop a D2D scheme with efficient spectrum utilization and interference reduction. Many survey papers have been published on these issues, but the fundamental concepts behind the D2D communication system require investigation. In this study, we investigated and analyzed the fundamental concepts behind the D2D communication system to develop an efficient D2D resource allocation scheme with reduced interference.
Reconfigurable modified wilkinson power divider using PIN diode switch
Authors: Edward N. , Shairi N. A. , Othman A. , Zakaria Z. , Bahri I. D. Saiful
Published: March 2020

In this paper, a reconfigurable modified Wilkinson Power Divider (WPD) was proposed. The operating frequencies of the proposed design were either at 2.5 GHz or 3.5 GHz for Worldwide Interoperability for Microwave Access (WiMAX) applications. This proposed design is reconfigurable in terms of its operating frequency by using PIN diode switches. PIN diode switch was used in this design to reconfigure the microstrip line length. By varying the bias voltage of the PIN diode to +5 V or -5 V, the proposed modified WPD can either operate at 2.5 GHz or 3.5 GHz. Rogers RO4350 (er=3.48, h=0.508 mm) was chosen as the substrate material and copper (thickness=0.035 mm) related to patch of design. Based on simulation results obtained from the Advanced Design System (ADS) software, the modified WPD shows good S-parameter performances at 2.5 GHz and 3.5 GHz. However, the measurement results exhibit frequency shifted. Even though there is a correlation between measurement results and simulation results, the resonant frequency was shifted due to parasitic reactance of the PIN diode.
Design and simulation hybrid filter for 17 level multilevel inverter
Authors: Hutabarat Marshal Andrea , Hasan Syafruddin , Rambe Ali Hanafiah , Suherman Suherman
Published: March 2020

The increasing of renewable energy applications such as solar cells, wind power, ocean thermal and HVDC (high voltage direct current) cause increment in the use of the inverter circuit. Harmonics that are generated by the inverter have negative impacts on the electrical equipment; harmonics cause excessive heat and may shorten the life of electrical equipment. A multilevel inverter is an arranged of cascaded inverters which aims to reduce total  harmonic distortion (THD). This paper proposes the design of 17 levels of a single-phase cascaded multilevel inverter with a hybrid filter insertion. By using PSIM simulator, the hybrid filter is proven reducing THD better than single pulse width modulation (SPWM) inverter. Installation of the hybrid filter is able to fix a maximum of 0.23% THDv and a maximum of 1.05% THDi. Hybrid filter installation reduces the value of THD to comply with IEEE 519-2014 standard.
ПРИЧИНИ ЧОЛОВІЧОГО БЕЗПЛІДДЯ: ПИТАННЯ ТА ВІДПОВІДІ
Authors: Khmil S. V. , Mayorova O. Yu. , Dudchuk I. V.
Published: March 2020

Мета дослідження – розглянути основні причини погіршення якості еякуляту чоловіків, а саме: негативний вплив навколишнього середовища, стиль життя та генетичні фактори. Матеріали та методи. У дослідженні використано бібліосемантичний та аналітичний методи. Результати дослідження та їх обговорення. Під час виконання дослідження було проаналізовано 65 джерел сучасної вітчизняної та зарубіжної літератури щодо причин погіршення якості еякуляту в чоловіків. Висновки. Аналіз літературних джерел показав погіршення якісних та кількісних показників еякуляту чоловіків протягом останніх років: зниження концентрації та загальної кількості сперматозоїдів, зменшення частки рухомих та морфологічно нормальних сперматозоїдів. Основними причинами таких змін є генетичні фактори; вплив негативних екологічних факторів (хімічне та радіоактивне забруднення, електромагнітне випромінювання); спосіб життя (шкідливі звички, неправильне харчування, професійна діяльність).
ЕФЕКТИВНІСТЬ ВИКОРИСТАННЯ ВІТАМІНУ D У КОМПЛЕКСНОМУ ЛІКУВАННІ БЕЗПЛІДДЯ У ЖІНОК ІЗ СИНДРОМОМ ПОЛІКІСТОЗНИХ ЯЄЧНИКІВ
Authors: Khmil M. S. , Khmil S. V. , Chudiiovych N. Ya. , Khmil-doswald A. S. , Malanchuk L. M.
Published: March 2020

Проблема безплідного шлюбу залишається актуальною в сучасному акушерстві, гінекології та репродуктології. Синдром полікістозних яєчників є однією з найчастіших причин ановуляторного безпліддя, що являє собою найпоширенішу ендокринну патологію у жінок репродуктивного віку, асоційовану з безпліддям, що характеризується гіперандрогенією, морфологічно кістознозміненими яєчниками та порушенням менструального циклу. У статті коротко представлено сучасні погляди на діагностику та лікування даної ендокринопатії. Висвітлено численні дані сучасної вітчизняної та зарубіжної літератури щодо ефективності використання вітаміну D у комплексному лікуванні та прегравідарній підготовці жінок із синдромом полікістозних яєчників. Доведено його зв’язок із фертильністю, важливу роль у патогенезі синдрому полікістозних яєчників, взаємозв’язок з метаболічними та репродуктивними порушеннями, роль у нормальному перебігу вагітності.
CLINICAL EFFECTS OF HUMAN IMMUNOGLOBULIN ADMINISTRATION IN WOMEN WITH RHESUS SENSITIZATION AT THE PRE-GRAVID STAGE
Authors: Chernievskaya S. G. , Rozhkovska N. M. , Marichereda V. G. , Yermolenko T. O.
Published: March 2020

The aim of the study – to evaluate changes in cellular immunity in rhesus-sensitized women in response to IVIG administration and the prognostic effectiveness of a method for the prevention of isoimmunization in the next pregnancy.

Materials and Methods. The study was performed on the basis of City Maternity Hospital No. 7" (Odesa) in 2014–2019. 37 rhesus-sensitized women were randomly splited in two clinical groups: main clinical group (n=19) where patients received human immunoglobulin for intravenous administration, and control group (n=18) where patients did not receive IVIG.

Results and Discussion. The state of cellular immunity in rhesus-sensitized women is characterized by a moderate decrease in the absolute and relative indices of T-lymphocytes while increasing the number of B-lymphocytes. The NK cell population did not differ from the control group. When analyzing subpopulations of T-lymphocytes, it can be concluded that the number of T-helper cells is increased and the number of T-suppressors is proportionally reduced. These changes explain the increase in the number of B-lymphocytes as a result of increasing antigenic load on cell receptors. In the group of women who received IVIG therapy, the ratio of chances of normalization of cellular immunity was 18.41 (95 % CI 2.62–166.74), T-helper – 14.93 (95 % CI) 2.45–107.8), T-suppressors – 14.57 (95 % CI 2.13 –127.57) and B-lymphocytes – 31.87 (95 % CI 4.1–333.41). According to the ROC analysis, the quality of the statistical model of IVIG application corresponds to AUC = 0.843 (95 % CI 0.689–0.941) According to the ROC analysis, the level of β-lymphocytes in the compared AUC groups = 0.58 (95 % CI 0.405–0.742).
РІВЕНЬ КАЛЬЦІЮ І ВІТАМІНУ D У ЖІНОК ІЗ ПОРУШЕННЯМИ МЕНСТРУАЛЬНОЇ ФУНКЦІЇ НА ТЛІ ХРОНІЧНИХ ГЕПАТИТІВ ТА ЙОГО КОРЕКЦІЯ
Authors: Lymar L. E. , Vdovychenko Yu. P. , Malanchyn I. M. , Lymar N. A.
Published: March 2020

Мета дослідження – визначення рівня кальцію і вітаміну D у жінок із порушеннями менструальної функції (ПМФ) на тлі  хронічного гепатиту (ХГ), його впливу на якість життя жінок та комплексна терапія.

Матеріали та методи. Обстежено 77 жінок репродуктивного віку (від 18 до 43 років) із ПМФ на тлі ХГ: аномальними матковими кровотечами (АМК) та дисменореєю. У контрольній групі було 30 жінок із ПМФ без патології печінки. Вивчено прояви ПМФ,  визначено рівень кальцію, вітаміну D, білкових фракцій при загостренні та ремісії ХГ, оцінено якість життя жінок.

Результати дослідження та їх обговорення. Пацієнток було розподілено на 2 групи залежно від методу лікування. Виявлено достовірне зниження рівня кальцію, вітаміну D та альбуміну, отримані результати підтверджують літературні дані. У жінок обох груп до лікування спостерігали помірний рівень зниження якості життя. Застосування в комплексній терапії комбінованого препарату кальцію з вітаміном D сприяло достовірному підвищенню рівня кальцію, вітаміну D та альбуміну. У 2 групі підвищився рівень якості життя за рахунок фізичного здоров’я. У доступній для обробки літературі ми не знайшли подібних досліджень при зазначеній коморбідній патології.

Висновки. У жінок з ПМФ на тлі загострення ХГ спостерігається зниження рівня кальцію та вітаміну D в крові, що призводить до погіршення якості життя. Комплексна терапія з урахуванням дефіциту кальцію та вітаміну D забезпечує тривалу ремісію та покращує якість життя пацієнток.
ОЦІНКА ЕХОГРАФІЧНИХ ПОКАЗНИКІВ У ЖІНОК З ГІПЕРПРОЛІФЕРАТИВНОЮ ПАТОЛОГІЄЮ ЕНДОМЕТРІЯ
Authors: Gorban N. Ye. , Kondratyuk V. K. , Raksha I. I.
Published: March 2020

Мета дослідження – визначити ехографічні особливості органів малого таза у жінок репродуктивного віку з неатиповою гіперпроліферативною патологією ендометрія (НГПЕ).

Матеріали та методи – Ультразвукове дослідження (УЗД) органів малого таза проведено 184 пацієнткам репродуктивного віку з НГПЕ, яких було поділено на 3 групи: І – жінки з неатиповою гіперплазією ендометрія (НГЕ) (n=60); ІІ – пацієнтки з поліпами тіла матки (ПТМ) (n=62); ІІІ – хворі з поєднаною НГПЕ (НГЕ+ПТМ) (n=62). Контрольну групу склали 30 жінок репродуктивного віку без наявності гінекологічної патології.

Результати дослідження та їх обговорення. Збільшення розмірів тіла матки встановлено у більшості хворих основних груп – у 126 (68,5 %) осіб. У 143 (77,7 %) хворих із НГПЕ ультразвукова картина характеризувалась вираженим поліморфізмом. НГЕ характеризувалась збільшенням товщини та зміною ехоструктури ендометрія, невідповідністю показників дню менструального циклу. При ПТМ спостерігали гетерогенність ендометрія та наявність ехопозитивних утворів овальної форми розміром 0,2–0,4 см однорідної структури. У 35,3 % жінок із НГПЕ виявлено неоднорідність тканини з переважанням гіперехогенних включень діаметром 0,1–0,3 см внаслідок вогнищ фіброзу і кальцинозу базального шару ендометрія, що є ехографічними ознаками хронічного ендометриту. Для наочності надано рисунки ультразвукових зображень різних видів НГПЕ.

Висновки. Саме трансвагінальне УЗД органів малого таза в жінок із НГПЕ є доступним, швидким та інформативним діагностичним методом у виявленні такої гінекологічної патології у жінок репродуктивного віку.
ХРОНІЧНИЙ ЕНДОМЕТРИТ ЯК ОДИН ІЗ ФАКТОРІВ НЕВДАЛИХ СПРОБ ІМПЛАНТАЦІЇ ЕМБРІОНІВ У ПРОГРАМАХ ДОПОМІЖНИХ РЕПРОДУКТИВНИХ ТЕХНОЛОГІЙ
Authors: Khmil S. V. , Chudiiovych N. Ya.
Published: March 2020

Безплідний шлюб залишається актуальною медико-соціальною проблемою в сучасному акушерстві, гінекології та репродуктології. На сьогодні все більша кількість подружніх пар використовує допоміжні репродуктивні технології як один із найефективніших методів лікування різних форм безпліддя. Одне із провідних місць у структурі захворювань, що впливають на фертильність жінок, займають запальні процеси органів малого таза. Хронічний едометрит являє собою хронічний запальний процес ендометрія, який негативно впливає на репродуктивну функцію жінок (знижує рецептивність ендометрія, сприяє виникненню репродуктивних невдач). У статті представлено основні аспекти етіології, патогенезу, діагностики та лікування хронічного ендометриту, тактику ведення жінок із даною патологією в програмах допоміжних репродуктивних технологій.
DISCOORDINATED LABOR ACTIVITY AND MODERN APPROACHES TO ITS CORRECTION
Authors: Lazurenko V. V. , Zvyagina N. Yu.
Published: March 2020

The aim of the study – to evaluate the course and outcome of childbirth for the mother and the fetus by comparing various methods of correction of discoordinated labor activity (DLA).

Materials and Methods. 120 women in childbirth were examined, of whom 90 women had DLA. Group 1 (control) consisted of 30 women with a physiological course of childbirth, group 2 – 30 women in labor, who underwent correction of the DLA according to the order of the Ministry of Health of Ukraine No. 676, dated 12/31/2004, group 3 – 30 women who underwent epidural anesthesia, group 4 – 30 women who underwent complex treatment using phosphatidylcholine.

The subject of the study was indicators of partograms of women in labor, fetal CTG, levels of adrenaline, norepinephrine, prostaglandin F2α, oxytocin, dopplerometry, and assessment of the condition of newborns.

Results and Discussion. In women with DLA, a premature rupture of the membranes was determined in 67 (74.5 %); indicators of adrenaline were increased (7.2±0.8) nmol/l. Under the influence of treatment, the adrenaline level decreased in group 4 to (3.5±0.5) nmol/l. There was an increase in the concentration of PGF2a during DLA to (177.2±6.9) ng/ml. The use of traditional therapy reduced the content of PGF2a to (134.1±5.1) ng/ml, the use of phosphatidylcholine to (111.7±4.8) ng/ml. Similar changes were observed in oxytocin parameters: an increase in the content during DLA (173.4±10.2) pg/ml, a decrease under the influence of traditional treatment (105.7±6.9) pg/ml and our proposed method of therapy (91.3±5.6) pg/ml.

The results of a Dopplerometric examination of women in labor with DLA indicated an increase in resistance in the uterine arteries and in the umbilical arteries. Studies have shown that in group 2, the Caesarean section was the lowest – 33.3 %, group 3 – 66.7 %, in group 4 – 40 %. Condition of the newborn: in group 2 of pregnant women in satisfactory condition 76.7 % of newborns were born, in the group 3 – 66.7 %, in group 4 – 73.3 %.

Conclusions. Based on the results of the evaluation of the outcome of labor, the use of phosphothydiolcholine in the complex treatment of discordination of labor can significantly reduce the frequency of operative half-divergence and improve the condition of the fetus and the newborn due to the normalization of biologically active substances in the blood of the mother and fetus, improvement of blood flow in the utero-placental complex and, as a result of normalization of maternity activities.
Isoflavone Intake and the Risk of Coronary Heart Disease in US Men and Women
Authors: Ma Le , Liu Gang , Ding Ming , Zong Geng , Hu Frank B. , Willett Walter C. , Rimm Eric B. , Manson JoAnn E. , Sun Qi
Published: March 2020

Background:

Whether soy products confer health benefits related to coronary heart disease (CHD) remains controversial because of inconsistent evidence.

Methods:

A total of 74 241 women from the NHS (Nurses’ Health Study; 1984–2012), 94 233 women from the NHSII (Nurses’ Health Study II; 1991–2013), and 42 226 men from the Health Professionals Follow-Up Study (1986–2012), who were free of cardiovascular disease and cancer at baseline, were included in the present analysis. Dietary data were updated every 2 to 4 years using a validated food frequency questionnaire. Nonfatal myocardial infarction and CHD deaths were adjudicated through reviewing medical records, death certificates, and other medical documents.

Results:

In these cohorts, 8359 incident CHD cases were documented during 4 826 122 person-years of follow-up. In multivariable-adjusted analyses, isoflavone intake was inversely associated with CHD (pooled hazard ratio [HR] comparing the extreme quintiles: 0.87 [95% CI, 0.81–0.94];
P
=0.008). Consumption of tofu, but not soy milk, was inversely associated with the risk of CHD, with pooled HRs (95% CIs) of 0.82 (0.70–0.95;
P
=0.005) and 0.87 (0.69–1.10;
P
=0.41), respectively, comparing ≥1 serving/week with <1 serving/month. Further analyses showed that, in women, the favorable association of tofu was primarily driven by stronger inverse association of tofu intake observed in younger women before menopause and postmenopausal women without hormone use (
P
interaction
=0.002).

Conclusions:

Higher intake of isoflavones and tofu was associated with a moderately lower risk of developing CHD, and in women the favorable association of tofu were more pronounced in young women or postmenopausal women without hormone use.