bluuebunny/crossref_metadata_2025 huggingface dataset:
TEACHERS’ PERCEPTIONS OF QUESTIONING AS PRE-TEACHING STAGE IN GENERAL ENGLISH CLASSES
Authors: Phan Ngoc Phuong Thanh , Nguyen Huan Buu
Published: August 2021

Research into questioning, a form of inquiry to engage students in active and purposeful responses has witnessed its crucial role in teaching English as a foreign or second language. In particular, questioning, from the Socratic philosophy, is an interactive process that involves student thinking and communication of ideas and knowledge for effective learning. However, teacher questioning has not received much attention in English as a foreign language (EFL) classroom context in higher education in Vietnam. Moreover, classroom questioning and teachers’ perceptions of this instructional practice facilitating students’ higher-order skills in non-English majored classes remained scarce. This study therefore examines such perceived use of questioning within non-English majored classes at tertiary context. This paper focuses on the interview data, which explored how seven teachers perceived their respective use of questioning related to active learning of students in General English classes. The findings reveal how teachers perceived questioning as effective in several ways. The findings extend the literature on questioning strategies by providing insightful views into how teachers used questions to promote active learning of students, tailor their existing practices, and make informed decision-making processes for their future undertakings. The paper concludes by presenting implications for teachers and students for the quality instruction and professional growth.

 

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THE RELATIONSHIP BETWEEN THE SCHOOL PRINCIPALS' LEVEL OF 21ST CENTURY SKILLS AND THEIR CAPABILITY TO MANAGE CHANGE AT SCHOOLS
Authors: Helvacı Mehmet Akif , Yörük Şirin
Published: August 2021

The purpose of this research is to determine the relationship between school administrators' levels of 21st century skills and their competencies in managing change, according to teachers' views. Moreover, it was investigated to reveal school administrators 21st century skills levels and their proficiency in managing change. In addition, it is aimed to reveal school administrators their 21st century skill levels and their proficiency in managing change. 290 teachers in Uşak participated in this quantitative research conducted in the relational survey model. As a research data collection tool, “The 21st Century Education Manager Skills Scale and the School Managers' Ability to Manage Change Scale were used. Correlation analyzes were also conducted along with descriptive statistics in order to determine the 21st century skills levels of school administrators and their proficiency in managing change. According to the results obtained, it has been seen that the 21st century skill levels of school administrators and their proficiency in managing change are at a very high level. Also, it has been determined that there is a high level of positive correlation between school administrators' proficiency levels of 21st century skills and their proficiency in managing change.

 

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MAKING A CASE ON SOCIAL INTERACTION OF PARENTS OF CHILDREN WITH AUTISTIC SPECTRUM DISORDERS: A STUDY OF SELECTED COMPOUNDS OF LUSAKA, ZAMBIA
Authors: Chalwe Kalumba Hellen , Mandyata Joseph , Kasonde-Ng’andu Sophie
Published: August 2021

Parenting a child is a challenging experience let alone parenting a child with a disability. The nature of the disability in a child goes with its complexity and it often puts parenting skills to the test. This study explores the experiences on social interactions of parents with Autistic Spectrum Disorder (ASD) in selected compounds of Lusaka, Zambia. The study used an interpretative phenomenological framework supported by qualitative approach. In-depth interviews were used to collect data. Non-probability criterion purposive sampling procedure was used to select participants. The sample size comprised of 10 parents with children with ASD. Qualitative data was analyzed thematically. The study revealed that parents had unique experiences in raising their children with ASD. These included; inadequate information on ASD; lack of support services; miscommunications between parents and children with ASD; stigmatization; lack of adequate sleeping time and negative attitude towards parents and their children with ASD. It was evident from the study that parents require supportive services including counselling to enable them to deal with the complexities that emanate from parenting children with ASD. In view of these the study recommended increased awareness on ASD; development, promotion and regular evaluation of intervention strategies parents use aimed at improving the daily lives of parents and their children with ASD in the study sites.

 

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JOB PROMOTION AND EMPLOYEE PERFORMANCE IN KENYA FORESTRY RESEARCH INSTITUTE HEADQUARTER IN MUGUGA, KIAMBU COUNTY
Authors: Ratemo Veronica , Bula Hannah , Felistus Makhamara
Published: August 2021

Employee performance at Kenya Forestry Research Institute has been found to be poor, with more than one third of organization’s employees failing to meet deadlines, regarding accomplishing their tasks or organizational targets. This study sought to investigate the effects of job promotion practices on employee performance in Kenya Forestry Research Institute in Muguga, Kenya. The study was anchored on expectancy theory. The study used a positivism philosophy and a descriptive research design. The unit of analysis was Kenya Forestry Research Institute. The target population was all the 178 staff working in Kenya Forestry Research Institute in Muguga. A sample of 121 respondents was selected through stratified random sampling. A semi-structured questionnaire was used in collecting primary data. A pilot study was conducted to ensure the data collection tool is reliable. Analysis of qualitative data was carried out through thematic analysis. Descriptive statistics focused on frequency distribution, percentages, mean and standard deviation. Components of inferential statistics include; Pearson correlation coefficient and multivariate regression analysis. Both descriptive and inferential data was analyzed by the help of SPSS Version 25. The results obtained were presented both in tables as well as figures (pie charts and bar graphs). The study found that job promotion practices have significant effect on employee performance in Kenya Forestry Research Institute. Further, the study found that employees acquire new skills through job promotion. Henceforth, the study recommends that Kenya Forest Research Institute Headquarter should consider leadership abilities, attitude of staff and review past performance when promoting staff so as to improve on their overall competency skills.

JEL: J01; J81

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SOCIO-DEMOGRAPHIC PREDICTORS OF JOB SATISFACTION AMONG SPORTS COUNCIL ADMINISTRATORS IN SOUTHERN NIGERIA
Authors: Adelakun J. A. , Orunaboka T. T. , Deemua G. A.
Published: August 2021

This study investigated socio-demographic predictors of job satisfaction among sports council administrators in southern Nigeria. The study was aimed at achieving two objectives. Two research questions were raised and answered while two null hypotheses were formulated and tested. The study employed a cross-sectional survey design. The population of the study comprised 3000 sports council administrators in southern Nigeria. Stratified random sampling technique was adopted to get the sample size of 450 sport administrators from the South-South, South-East and South-West sub-regions in Southern Nigeria. An instrument tagged ‘Questionnaire on Socio-Demographic Predictors of Job Satisfaction’ (QSDPJS) was used for data collection. A reliability coefficient of 0.86 was obtained for the instrument. Percentages, Mean score ), standard deviation and multiple regression were the statistical tools used for data analysis. Some of the findings showed that sixty per cent (60%) of sports administrators in southern Nigeria are not satisfied with their job. Also, socio-demographic variables of age, gender, educational qualification, length of service could jointly predict job satisfaction of state sports council administrators. Based on these findings, it was concluded that the observed poor performance of most southern states in various national sports competitions in Nigeria can be attributed to low extent of job satisfaction among sports council administrators. It was therefore recommended that state governments in the southern sub-regions of Nigeria should make prompt payment of sports council workers at the end of the month a priority and sport administrators’ salary, welfare packages and other emoluments should be enhanced.

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“COMMAND WITHOUT DEBASEMENT”: SUGGESTIONS FOR IMPROVED INTRA-FORCE RELATIONS IN NIGERIA POLICE FORCE THROUGH EXCELLENCE PUBLIC RELATIONS
Authors: Ikeh Chinyere
Published: August 2021

This paper highlights the imperative of effective intra-relations within the Nigerian Police Force. Most discourses of public relations in relation to the Nigeria Police Force focus more on the external publics with less interest on the internal public. Being a hierarchical organization characterized by top-down communication expressed in form chain of command, it assumes that the police force has no use for symmetrical communication which is the hallmark of Grunig’s excellence theory of public relations. However, this study proves otherwise, that excellent public relations can be practiced in the force when members of the organization especially the superiors realize and operationalize the habit of commanding without debasing their subordinates. In doing this, the status of intra-force relations of the Nigeria police force will be greatly improved.

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INFLUENCE OF SCHOOL RESOURCES ON ACADEMIC PERFORMANCE OF VISUALLY IMPAIRED LEARNERS IN INTEGRATED PUBLIC PRIMARY SCHOOLS IN BARINGO COUNTY, KENYA
Authors: Konga Dinah Jepkorir , Cheboi Stephen Tomno
Published: August 2021

Despite the provision of school resources by Kenyan government through the Ministry of Education, there has been an outcry from stakeholders owing to dismal performance among Visually Impaired Learners at Kenya Certificate of Primary Education examination in Marigat and Kabartonjo Sub-Counties. The purpose of this study was to establish the extent to which school resources influence academic performance of visually impaired learners in integrated primary schools in Baringo County. The study adopted mixed methods methodology where data was collected by use of questionnaires, interview, and observation guides to obtain both quantitative and qualitatively data, respectively. The target population involved501 participants comprising 2 head teachers, 68 regular teachers, 49 VI learners, 380 sighted learners and 2 Educational Assessment Resource Centers (EARC) officers. From this population, a total sample of298 participants was drawn. Simple random sampling technique was used to draw 59 regular teachers, 191 sighted learners and 44 VI learners, while 2 EARC officers and 2 head teachers were purposively sampled. Data was collected using questionnaires for teachers and sighted learners, interview guide for heard teachers and EARC, and observation checklist for Visually Impaired respondents. The tools were piloted to establish their reliability and adequately validated. The quantitative data was analyzed using descriptive statistics while thematic analysis was used for qualitative data. The study found out that inadequate learning materials was a major cause of low academic performance of VI learners in Marigat and Kabartonjo integrated public primary schools. It further established that there were inadequate learning resources, support services and a learning environment that was not conducive for VI learners. The study recommends that the government provides more learning resources to VI learners and school management to provide barrier free learning environment. This study results would be of great value to teachers, parents, head teachers, schools, stakeholders, and Ministry of Education in enhancing academic performance of the V.I learners in Integrated schools.

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Verbraucherschutz aus Sicht der Informationsökonomik - Rechtfertigung, Maßnahmen und Erweiterungsbedarf
Authors: Döring Thomas
Published: August 2021

Im Rahmen des vorliegenden Beitrags erfolgt zunächst eine Erklärung des Verbraucherverhaltens und seiner marktbezogenen Implikationen, wie es sich aus informationsökonomischer Sicht darstellt (Kapitel 2). Hierzu zählen sowohl eine Erläuterung der Auswirkungen unvollständiger Information über die Marktbedingungen auf die Qualität der Kaufentscheidungen von Konsumenten (Kapitel 2.1) als auch die Folgen einer asymmetrischen Informationsverteilung zwischen Anbietern und Nachfragern für die Effizienz der Marktergebnisse (Kapitel 2.2). Eine eingehende Betrachtung der Informationseigenschaften von Gütern und Dienstleistungen vor und nach dem Kauf liefert zudem Einsichten über das unterschiedliche Ausmaß an Schutzbedürftigkeit der Verbraucher (Kapitel 2.3). Die sich daraus ableitenden Anknüpfungspunkte für eine ökonomische Rechtfertigung verbraucherpolitischen Handelns stehen im Mittelpunkt der weiteren Überlegungen (Kapitel 3). Dabei wird zwischen privaten und öffentlichen (Schutz-)Maßnahmen der Verbraucher unterschieden. Erstere resultieren aus der Logik des Marktgeschehens selbst und sind insofern im Vorfeld staatlicher Markteingriffe anzusiedeln (Kapitel 3.1). Dem werden solche staatlichen Regulierungen gegenübergestellt, die erforderlich sind, um bestehende Informationsdefizite der Konsumenten, die nicht durch Marktlösungen abgebaut werden können, auszugleichen (Kapitel 3.2). Den Abschluss des Beitrags bilden Überlegungen, die auf bestehende Beschränkungen in der informationsökonomischen Betrachtung eingehen, um damit auf die Notwendigkeit zu einer Erweiterung der Analyseperspektive von Verbraucherverhalten und Verbraucherpolitik zu verweisen (Kapitel 4).
Interaktionseffekte zwischen Gemeinde- und Kreisebene im nordrhein-westfälischen Finanzausgleich - eine aktualisierte Bewertung aus finanzwissenschaftlicher Sicht
Authors: Döring Thomas
Published: August 2021

Am kommunalen Finanzausgleich in Nordrhein-Westfalen wurde wiederholt kritisiert, dass die Verortung und Ausgestaltung des Soziallastenansatzes auf Gemeindeebene im Zusammenspiel von Gemeinde- und Kreisfinanzausgleich sowie unter Berücksichtigung der „Mischfinanzierung“ der Kreise in Form von Zuweisungen und Umlagen zu unerwünschten Umverteilungseffekten im kreisangehörigen Raum führe Dies gelte insbesondere mit Blick auf das Verhältnis von kreisangehörigem Raum zu kreisfreien Städten, aber auch im Verhältnis der Kreise mit relativ hohen Soziallasten (einschließlich ihrer Gemeinden) zu den übrigen Kreisen, wobei eine Benachteiligung der jeweils erstgenannten Gruppe an Gebietskörperschaften gegenüber der zweitgenannten behauptet wird. Mit dem vorliegenden Beitrag sollen unter Berücksichtigung aktuellerer Daten vor allem die Interaktionseffekte im kreisangehörigen Raum einer in diesem Sinne erweiterten Untersuchung unterzogen werden, um feststellen zu können, ob es sich hierbei um systeminadäquate Verwerfungen bzw. Verzerrungen handelt, die aus finanzwissenschaftlicher Sicht einer entsprechenden Korrektur bedürfen, oder lediglich um Effekte, die vor allem mit Blick auf den Soziallastenansatz als systemkonform zu bewerten sind.
SEGMENTASI DAN PERAMALAN PASAR RETAIL MENGGUNAKAN XGBOOST DAN PRINCIPAL COMPONENT ANALYSIS
Authors:   Universitas Methodist Indonesia, Siringoringo Rimbun , Perangin-angin Resianta , Purba Mufria J.
Published: August 2021

The growth of the online retail market in Indonesia is an excellent business opportunity. It is predicted that this growth will continue to move upward due to the increasing internet penetration. With greater exposure to brands, products and offerings, consumers become smarter and wiser in their purchasing decisions. Offering goods and services that match the tastes and behavior of consumers is very important to maintain business continuity. So far, the models developed are divided into two major parts, namely the time series approach and machine learning. In this study, segmentation and forecasting of online retail sector sales were carried out using extreme gradient boosting (XGBoost). The data used in this study is an online retail dataset obtained from the UCI repository. The k-means clustering (KMC) method is applied to determine the target or data class. Principal component analysis (PCA) is applied to reduce data dimensions by eliminating irrelevant features. Model evaluation is based on a confusion matrix and macro average ROC curve. Based on the research results, XGBoost can perform retail data classification well, this can be seen through confusion matrix metrics and ROC curves.
EVALUASI PENERAPAN SISTEM INFORMASI AKUNTANSI PERSEDIAAN BAHAN BAKU PADA PT. CIOMAS ADISATWA MEDAN
Authors:   Universitas Methodist Indonesia, Purba Melky Alessandro , Purba Dimita H. P. , Jamaluddin Jamaluddin , Silalahi Mulatua P.
Published: August 2021

This study aims to determine the application of accounting information system for raw material inventories at PT. Ciomas Adisatwa Medan. To find out the application of the accounting system for raw material inventory at PT. Ciomas Adisatwa Medan, data collection techniques were used, namely literature study and field research techniques. While the analysis technique used is a descriptive method. From the results of the study, it can be concluded that application of the accounting information system for raw material inventory at PT. Ciomas Adisatwa Medan has been implemented not good, because there is still inaccurate information that is the demand for raw materials is not in accordance with what is received by the production. Weaknesses Oversight of raw material inventory in warehouses is piling up and is not suitable for processing. The delay in the schedule of order for supporting raw materials to be processed, so the production process does not run properly. The procedures used in the accounting information system for raw material inventory at PT. Ciomas Adisatwa Medan, among others, procedures for requesting raw materials, procedures for receiving raw materials and procedures for issuing raw materials.
PENGEMBANGAN PERANGKAT IoT MONITORING KUALITAS UDARA DALAM RUANGAN MENGGUNAKAN MIKROKONTROLLER BERBASIS ANDROID
Authors:   Universitas Methodist Indonesia, Silitonga Nogar , Telaumbanua Yuniman , Simanullang Harlen Gilbert
Published: August 2021

Air quality in a room is a problem that needs to be considered because it can affect human health. Therefore, we need a system that can monitor LPG, CO2, and cigarette smoke levels to determine the value of air quality levels in a room. Air pollution levels can be measured with the MQ-2 sensor to detect levels and an Android-based application as an information viewer. This study aims to build a monitoring application for LPG, CO2, and cigarette smoke levels based on the wireless ESP8266 sensor network in the room. The level monitoring application is built with the Java programming language, Firebase, and Arduino software. The application development stage includes analysis, system design, implementation, and testing. The level monitoring application that is made can display the results of monitoring data. So those users can find out the measurement data of a level that is in a room with a series of sensors used. The result is research on the use of this device can be used as a tool to monitor air quality in a room.
PENERAPAN METODE FRAME BY FRAME DALAM PEMBUATAN ANIMASI TATA CARA HAJI SESUAI SUNNAH RASUL MENGGUNAKAN APLIKASI 3DS MAX
Authors:   Universitas Harapan, Syahfaridzah Aldina , Khairunnisa Khairunnisa , Dharmawati Dharmawati
Published: August 2021

Advances in technology in the field of information are developing very rapidly at this time, especially information in the field of animation. The animation is a visual form that moves and is used to present information and learning that is difficult to understand if delivered in general. The use of animation media is specially made to find out the procedures for the Hajj pilgrimage in order to increase knowledge for someone who wants to perform the Hajj or want to know the Hajj procedures because Hajj is the fifth pillar of Islam where if someone carries it out, much wisdom will be gained. Information about the pilgrimage procedures is packaged with 3D animation and created using 3Ds Max application and the frame by frame method, where all movements of the animation are arranged using frames. So that the resulting learning media, namely animated videos that add insight and information for someone because it is packaged with media that is more attractive and easy to understand, namely animation.
Histopathological Review and Distribution of Granulomatous Inflammatory Disorders in Makurdi, North Central Nigeria
Authors: Ngbea JA , Agwa MN , Gyenger DT , Nyaga T , Akpor OI , Vhriterhire RA
Published: August 2021

Granulomatous inflammation is a pattern of chronic inflammation characterized by the presence of granulomas consisting of microscopic aggregates of macrophages transformed into epithelioid cells surrounding by a collar of lymphocytes and occasioned plasma cells. The study aimed to determine the distribution by tissue site, histological patterns of granulomatous inflammatory disorders in Benue State University Teaching Hospital (BSUTH), Makurdi over a 5-year period. This was a 5 year (March 2013 – February 2018) retrospective study of all cases diagnosed as granulomatous inflammatory disorders on Haematoxylin and Eosin-stained sections at the Anatomical pathology Department. Ziehl-Neelsen special stain was also done on all specimens. A total of two hundred and thirty-six (236) cases of granulomatous inflammatory disorders were diagnosed, analysed and categorized based on the tissue site, on Haematoxylin and Eosin-stained sections; Ziehl-Neelsen special stain was done on all cases. The most common sites were cervical lymph nodes, appendix, skin, testicular tissues etc with the Eyelid been the least common site.
Computational Performance of GTD-RT Applied for Evaluation of Electromagnetic Scattering on Rough Surfaces
Authors: Farahat Asmaa , Hussein Khalid
Published: August 2021

In this paper, a new robust computational method that applies the geometrical theory of diffraction (GTD) in conjunction with the ray tracing (RT) technique is developed to evaluate the electromagnetic scattering pattern due to a plane wave represented as beam of parallel rays incident on a rough surface of quite arbitrary statistical parameters. The development of the proposed technique is explained in detail taking into consideration the generation of the geometrical model of the rough surface. The Fresnel reflection model is applied under the assumption of arbitrary electrical and
optical properties of the rough surface material. Also the polarization of the plane wave primarily incident on the rough surface is taken into consideration. The algorithm
developed in the present work accounts for multiple bounces of an incident ray and, hence, it can be considered arbitrary higher-order GTD-RT technique. The accuracy of the obtained results is verified through the comparison with the experimental measurements of the scattering pattern of a light beam incident on rough sheets with specific statistical properties. The numerical results of the present work are concerned with investigating the dependence of the scattering pattern on the surface roughness, refractive index, angle of incidence, and the resolution of the geometric model of the rough surface. Also, it is shown that, for limited resolution of the rough surface model, the accuracy of the calculated scattered field depends on the angle of incidence of the primary beam and the surface roughness.
Interpretation Method of GATEM Data based on PID Controller Iteration Downward Continuation Method
Authors: Guan Shanshan , Du Bingxuan , Li Dongsheng , Wang Yuan , Zhu Yu , Wu Qiong , Ji Yanju
Published: August 2021

The Ground-source Airborne Time-domain Electromagnetic (GATEM) system has advantages for high efficiency and complex areas such as mountainous zone. Because of ignoring the impact of flight height, the section interpretation method seriously affects the interpretation and imaging accuracy of shallow anomalies. The PID controller iteration downward continuation method is proposed. Based on the original iteration
continuation method, the differential coefficient and integral coefficient are added. The result shows that the new method remarkably decreases the iteration number, and the accuracy are verified by comparison with the numerical integration solution. The PID controller iteration downward continuation method is applied to the interpretation of GATEM data. For synthetic data, the interpretation results of continued electromagnetic
response are closer to the true model than the z = 30 m interpretation results. The method is also applied to GATEM field data in Yangquan City, Shanxi Province, China. The interpretation results perform reliability using PID controller iteration downward continuation method in a GATEM field.
The Behavior of Electromagnetic Wave Propagation in Photonic Crystals with or without a Defect
Authors: Basmaci Ayse
Published: August 2021

In this study, the electromagnetic wave propagation behavior of two-dimensional photonic crystal plates with a defect is investigated. For this purpose, the partial differential equation for the electromagnetic wave propagation in various photonic
crystal plates containing a defect or not is obtained by using Maxwell’s equations. The defect is also defined in the electromagnetic wave propagation equation appropriately. In order to solve the electromagnetic wave propagation equation, the finite differences method is used. The material property parameters of the photonic crystal plates are determined with respect to the defects. Accordingly, the effects of material property parameters on electromagnetic wave propagation frequencies, phase velocities, and group velocities are examined. The effects of the size and position of the defects on the
electromagnetic wave propagation frequencies are also discussed. The highest electromagnetic wave propagation fundamental frequency value obtained from the analyses performed is 1.198 Hz. This fundamental frequency value is obtained for the electromagnetic wave propagation in the t-shaped photonic crystal plate. Electromagnetic field distribution maps for the fundamental frequencies of the photonic crystal plates whose electromagnetic wave propagation behaviors are examined are obtained with the ANSYS package program based on the finite differences time-domain
(FDTD) method.
Design of Microstrip Parallel-Coupled Lines with High Directivity using Symmetric-Centered Inductors
Authors: Sonasang Somchat , Angkawisittpan Niwat
Published: August 2021

A technique for directivity improvement of the microstrip parallel-coupled lines using symmetric-centered inductors is presented in this paper. The design procedure of the symmetric-centered inductors using the closed-form equations is given. The proposed technique was performed with a design at the operating frequency of 0.9 GHz on an FR4 substrate. Validity of the proposed technique is verified by simulations and measurements in comparisons with conventional parallel-coupled lines. The measured results exhibit the isolation of -30.10 dB and directivity of 19.28 dB at the operating frequency of 0.9 GHz. The directivity from the measured results is improved by more than 4 dB at 0.9 GHz and more than 6 dB at 1.05 GHz compared with the conventional parallel-coupled lines. In addition, the proposed technique for the microstrip parallel-coupled line can achieve a high directivity with the compact size (21.0 mm x 4.70 mm). The novelty of this paper is by introducing the proposed and closed-form design equations for the compact symmetric-centered inductors with high directivity.
Compact Dual-Passband Three-Dimensional FSS with Good Angular Stability and Both-Side Fast Roll-Off Characteristics
Authors: Yu Zhengyong , Li Baozhu , Ding Shenggao , Tang Wanchun
Published: August 2021

A compact dual-passband three-dimensional (3D) frequency selective surface (FSS) is proposed based on multiple square coaxial waveguides (SCWs), which exhibits good angular stability and both-side fast roll-off characteristics. The unit cell of the proposed 3D FSS is composed of one parallel plate waveguide (PPW) propagation path and two SCW propagation paths. By etching a centered annular slot, each SCW path forms two identical short SCWs. Each short SCW inherently generates one square slot resonance. In each SCW path, on the account of electromagnetic coupling between two square slot resonators provided by two short SCWs, the square slot resonant mode will split into even-/odd-resonant modes. Accordingly, each SCW path can provide a flat second-order passband with two transmission poles. Due to the reflection and out of phase of electromagnetic waves, four transmission zeros located at both sides of the passbands are introduced for high frequency selectivity, realizing both-side fast roll-off performances. In order to explain the operating principle, the electric-field distributions at transmission-zero/pole frequencies are investigated. Finally, an FSS prototype is fabricated and measured, and the results exhibit good angular stability for both TE and TM polarizations under incident angles from 0° to 60°. In addition, the proposed 3D FSS
has a compact unit cell.
Development and Verification of Indirect Lightning-Induced Transient Protection Circuit for Avionics System
Authors: Kim Sung-Yeon , Park Jeong-Su , Lee Wang-Sang
Published: August 2021

In this paper, an indirect lightning-induced transient protection circuit for avionics system is proposed, and its effectiveness is verified. The proposed circuit consists of a metal oxide varistor (MOV), a transient voltage suppression (TVS) diode, and a resistor. Compared with the conventional circuits (MOV or TVS diode), the improved noise suppression of the proposed circuit against indirect lightning strikes are experimentally verified in accordance with radio technical commission for aeronautics (RTCA) DO-160G Sec. 22. The highest attenuation levels of indirect lightning strike WF5A reference voltage and current signals are approximately 91.0% and approximately 98.4% for the input lightning signals, respectively.
Tunable Terahertz Plasmon-Induced Transparency in Resonator-Coupled Dirac Semimetal Waveguides
Authors: Wang Daobin , Yang Jiahuan , Wang Wei , Yuan Lihua , Li Xiaoxiao
Published: August 2021

The bulk Dirac semimetal (BDS) is an interesting material, similar to graphene, which can
dynamically adjust its optical properties via a variation in its Fermi energy or electrical voltage. In this work, a BDS-based plasmonic device, which enables tunable terahertz plasmon-induced transparency, was proposed and designed. By using the finite element method, the surface plasmon polariton and plasmon-induced transparency of this device were systematically investigated. The results demonstrate that the plasmon-induced transparency of such device can be dynamically tuned by varying its Fermi energy. When the Fermi energy changes from 55 meV to 95 meV, the maximum group delay time of the device increases from 13.2 ps to 21 ps. In the case of a cascading device, the maximum
group delay time can be further pushed up to 44.57 ps. The influence of the ambient refractive index on the optical properties of the proposed device was also considered and investigated.
Design and Analysis of a Triple-band Non-zonal Polarization Electromagnetic Metamaterial Absorber
Authors: Wu Han , Ji Shijun , Zhao Ji , Luo Zhiyou , Dai Handa
Published: August 2021

A facile design of a novel triple-band electromagnetic metamaterial absorber (MMA) with
polarization insensitive property is proposed in this paper. Each unit of the MMA consists of upper copper resonator and bottom copper plate with middle dielectric FR-4 between them. The MMA performs three absorption peaks at 16.919 GHz, 21.084 GHz and 25.266 GHz with absorption rates 99.90%, 97.76% and 99.18%, respectively. The influence of the main structural parameters on the frequencies and absorption rates is analyzed. The absorption mechanism of the absorber is explained by electric field, magnetic field and surface current distributions, which is supported by the electromagnetic parameters, affected with magnetic resonance. The polarization-insensitivity of TE wave is verified by observing the effects of the polarization angle change from 0-90º. The MMA can be applied in radiation, spectrum imaging detector, electromagnetic wave modulator, and so on.
Radiation Pattern Synthesis and Mutual Coupling Compensation in Spherical Conformal Array Antennas
Authors: Khan Taimur , Khattak Muhammad , Tariq Adnan
Published: August 2021

This paper presents a novel technique based on Hybrid Spatial Distance Reduction Algorithm (HSDRA), to compensate the effects of deformity and mutual coupling occurred due to surface change in conformal arrays. This antenna surface deformation shifts the position of null points and loss of the main beam resulting in reduced antenna gain along with substantial undesirable effects on the antenna performance. The
proposed algorithm, which cumulatively incorporates the Linearly Constraint Least Square Optimization (LCLSO) and Quadratically Constraint Least Square Optimization (QCLSO) techniques, is formulated to minimize/reduce the absolute distance between the actual (simulated/measured) radiation pattern and the desired radiation pattern while keeping the direction of main beam and nulls position under control. In particular,
a 4x4 conformal microstrip phased array from planar surface is deformed to prescribe spherical-shape surface with various radii of curvature, is validated. For the enhancement of Gain of the conformal array antenna, Gain Maximization Algorithm is also proposed, the simulated results of which is compared to the traditional Phase compensation technique and unconstraint least squares optimization. The analytical results for both planar and spherical deformed configurations are first evaluated in MATLAB and then validated through Computer Simulation Technology (CST).
Parameter Design of Conformal PML Based on 2D Monostatic RCS Optimization
Authors: Zhang Yongjie , Deng Xiaofeng
Published: August 2021

In this study, 2D finite element (FE) solving process with the conformal perfectly matched layer (PML) is elucidated to perform the electromagnetic scattering computation. With the 2D monostatic RCS as the optimization objective, a sensitivity analysis of the basic design parameters of conformal PML (e.g., layer thickness, loss factor, extension order and layer number) is conducted to identify the major parameters of conformal PML that exerts more significant influence on 2D RCS. Lastly, the major design parameters of conformal PML are optimized by the simulated annealing algorithm (SA). As revealed from the numerical examples, the parameter design and optimization method of conformal PML based on SA is capable of enhancing the absorption effect exerted by the conformal PML and decreasing the error of the RCS calculation. It is anticipated that the parameter design method of conformal PML based on RCS optimization can be applied to the cognate absorbing boundary and 3D electromagnetic computation.
Broadband CPW-Fed Circularly Polarized Square Slot Antenna for Universal UHF RFID Handheld Reader
Authors: Ma Rui , Feng Quanyuan
Published: August 2021

This paper presents a new coplanar waveguide (CPW)-fed circularly polarized square slot
antenna (CPSSA). The proposed antenna uses an inverted Z-shaped feedline protruded from the signal line of the feeding CPW. Circularly polarized (CP) radiation can be achieved by adequately inserting the arc-shaped grounded strip into the upper right corner of the square slot. The widened vertical tuning stub on the L-shaped grounded strip can improve impedance matching and axial ratio (AR) performance. The measured results indicate that the 10 dB impedance bandwidth is 620 MHz (652-1272 MHz), and the 3 dB axial ratio bandwidth is 320 MHz (840-1160 MHz), which has a broadband characteristic. In the range of the universal UHF RFID band, the measured peak gain is about 4.4 dBi. The proposed CPSSA uses low-cost FR4 material as the dielectric substrate. The overall size of the antenna is 119 × 119 × 0.5 mm3. The proposed antenna has a simple structure, easy processing, good performance, wide operating bandwidth, and dual circular polarization characteristic. It can be applied to the universal UHF RFID handheld reader environment.
Compact 2x2 and 4x4 MIMO Antenna Systems for 5G Automotive Applications
Authors: Khalifa Mohamed , Yacoub Ahmad , Aloi Daniel
Published: August 2021

In this paper, three Vehicular multiple-input multiple-output (MIMO) 5G antenna systems have been constructed from using a newly developed 5G cellular branched Monopole element are presented. The MIMO systems operates in the 5G frequency bands (617MHz-
5GHz) with a compact structure that allows for up to four elements to be integrated in the same Sharkfin. The 3 configurations of MIMO systems have been simulated using HFSS, measured on a 1-meter ground plane (GND), then measured on a vehicle roof and the
individual antenna parameters in terms of reflection coefficient and efficiency have captured. The MIMO antenna systems performance in terms of passive isolation, combined radiation pattern, envelope correlation coefficient (ECC), and diversity gain (DG) have been reported and discussed.
Improved Thevenin Equivalent Model of MMC Considering Pre-charge Conditions and DC Side Fault Conditions
Authors: Jin Enshu , Song Zhenyu , Yang Xiaofan , Yu Xin
Published: August 2021

The traditional Thevenin equivalent Modular Multilevel Converter (MMC) model has poor versatility for the two working conditions of pre-charging and DC-side faults. In this paper, an improved Thevenin equivalent MMC model considering pre-charge conditions and DC side fault conditions is proposed. The model divides the pre-charging condition into a Controllable charging stage and an Uncontrollable charging stage. The DC-side fault condition is divided into the pre-blocking and post-blocking conditions of the converter. The circuit characteristics are analyzed, and the equivalent model topology is comprehensively improved to make it suitable for full-condition simulation, and a control strategy suitable for the equivalent model is proposed. The detailed model and the proposed improved equivalent model were built in PSCAD/EMTDC for comparison and analysis. The simulation results shows that the improved equivalent model can be applied to various working conditions, and the versatility of the traditional Thevenin equivalent model is improved.
Measuring Factor Affecting Indonesia’s Seafarers Retention
Authors: Samosir Christopher , Maharani Anita , Burhanuddin Muchlis
Published: August 2021

The purpose of this study was to determine the extent to which human resource management contributes to employee retention. This study refers to concepts related to human resource management and several studies that show the factors influenced by employee retention. This research approach is quantitative, with the research subjects are employees who work in the sea crossing business. Based on the research results on marine employees of the company, the managerial implications intended for companies engaged in sea crossing services are that there is an influence of placement, compensation, and corporate culture variables on employee retention, which has a positive and significant effect. From the research results, corporate culture is not a moderator of placement and compensation variables on retention, so companies need to re-assure other variables that strongly influence the weak relationship between variables that can increase employee retention.
A Retrospective Observational Study of Chlorine Dioxide Effectiveness to Covid19-like Symptoms Prophylaxis in Relatives Living with COVID19 Patients
Authors:   Centro Médico Jurica, Querétaro, México, Alonso Manuel Aparicio
Published: August 2021

To date, there is no effective prophylactic agent to prevent COVID-19. However, the development of symptoms similar to covid19 could be prevented with an aqueous solution of chlorine dioxide (ClO2). This retrospective study evaluated the effectiveness of an aqueous solution of ClO2 (CDS) as a prophylactic agent in 1,163 family members living with positive/suspected COVID19 patients. Prophylactic treatment consisted of 0.0003% chlorine dioxide solution (CDS) orally for at least fourteen days. Family members in whom no reports of the development of covid19-like symptoms were found in the medical history were considered successful cases. The efficacy of CDS in preventing covid19-like symptoms was 90.4% (1,051 of 1,163 relatives did not report any symptoms). The comorbidities, sex and severity of the illness of the sick patient did not contribute to the development of symptoms similar to covid19 (P = 0.092, P = 0.351 and P = 0.574, respectively). However, older relatives were more likely to develop covid19-like symptoms (ORa = 4.22, P = 0.002). There was no evidence of alterations in blood parameters or in the QTc interval in relatives who consumed CDS. The recent findings regarding Chlorine Dioxide justify designing clinical trials to assess its efficacy for preventing SARS-CoV-2 infection.
Implementation of South Korea's Chanbogo Submarine Purchase Policy
Authors:   Graduate School, Faculty of Defense Strategy, Indonesia Defense University,Jl. Sentul - Citeureup, Sentul, Kec. Citeureup, Bogor, Jawa Barat 16810, Indonesia, Supriyono Supriyono
Published: August 2021

A strong national defense system does not require consideration of empathy, including the geographical factors of the country being examined, the national resources of a country, an analysis of possible threats that will arise, and the development of information technology. Defense is something that is fundamental to the survival of a country. Cooperation between Indonesia and South Korea in the defense industry is centered on the development of the changbogo class submarine and the development of the KFX / IFX fighter aircraft. Seen from the Government's policy, it can be seen that the domestic industry is unprepared to support the independence of the defense industry. This unpreparedness can be caused by the absence of supporting infrastructure or financial support for mass production of defense and security equipment. This scientific work is expected to provide recommendations in defense policy regarding submarine development. This study uses a scientific approach with qualitative descriptive methods and uses implementation tehory by George C. Edward. The results of this study a policy review of South Korea’s Submarine purchase policy . The conclusion of this study are constraints and challenges faced in improving submarines, particularly related to the ability of PT. PAL Indonesia is still limited in the manufacture of the DSME 209/1400 submarine.
Dynamic of Risk Management and Intermediate Functions of Commercial Banks: The Supply Side Evidence from Nigeria
Authors:   Department of Banking and Finance Rivers State University, Port Harcourt, Nigeria, Nwakaego Akani Elfreda
Published: August 2021

This study investigated the relationship between risk management and financial intermediation of quoted commercial banks in Nigeria. Panel data were sourced from the Nigeria Stock Exchange for a period that spans 2009 to 2018. Financial intermediation was measured domestic credit of the commercial banks. Domestic credit was modelled as the function of Risk diversification, Basel compliance, risk transfer, credit securitization and risk retention and risk evaluation. Multiple regressions were formulated to ascertain the relationship between risk management and capital investment decision of commercial banks. Panel Unit root test was utilised to establish the stationarity of the data. Panel cointegration, and granger causality test analyse the data. The panel unit root test proved presence of unit root at first difference and concluded that the variables were integrated in the order of 1(I). The study found that, there is a significant relationship between risk management and domestic credit decision, of the quoted commercial banks. The panel cointegrations show the presence of long run relationship between the endogenous variables and the exogenous variables while the granger causality test found uni-directional causality among the variables. From the findings, the study concludes that risk management have significant relationship with domestic credit decisions of the commercial banks. The study recommends that to mitigate the riskiness of banking operations, more avenues for risk diversification should be explored. Although Basel compliance enhances domestic credit decision, its implementation should be done cautiously and in consideration of the intricacies and peculiarities of the Nigerian banking space, as it impinges on most domestic credit decisions.
Assessment of the Legal and Institutional Framework for the Management of Fiscal Liabilities Arising from Public-Private Partnerships (PPPs) in Nigeria
Authors:   Research Fellow, African Procurement Law Unit, Department of Mercantile Law, Stellenbosch University. South Africa and Honorary Senior Research Associate, The Bartlett School of Construction & Project Management, University College London, London, United Kingdom., Nwangwu George
Published: August 2021

The procurement of infrastructure projects through the use of PPPs has a number of advantages including the potential of reducing life cycle costs, better project risks management and improved service delivery to mention a few. However, PPPs inevitably give rise to liabilities whether explicit or contingent. These liabilities where not properly managed may have adverse economic consequences for countries. This paper finds that whilst Nigeria has appropriate legal and institutional structures for managing fiscal liabilities generally, such structures are not designed or appropriate to deal with fiscal liabilities arising from PPPs. The paper makes suggestions on how this shortcoming may be addressed.
Investment Policy and Net Book Value of Quoted Manufacturing Firms: Dynamic Panel Data Evidence From Nigeria
Authors:   Department of Banking and Finance, Rivers State University, Nigeria, Chikwendu Adibe Francis
Published: August 2021

This study examined the relationship between investment policy and dynamic of net book value of quoted manufacturing firms in Nigeria. Panel data of 15 quoted manufacturing firms was collected from the annual reports of the manufacturing firms from 2010-2019. Stock prices of the quoted firms was modeled as the function of short term portfolio investment, subsidiary investment, long term portfolio investment and long term investment. Multiple regressions were formulated. Panel data methodology was employed while the fixed effects model was used as estimation technique at 5% level of significance. Fixed effects, random effects and pooled estimates were tested while the Hausman test was used to determine the best fit. Panel unit roots and panel cointegration analysis were conducted on the study. The study found that the independent variables explained 69.1 percent of the systematic variation in net book value of the quoted manufacturing firms. Long term investment and subsidiary investment have positive relationship with net book value of the quoted manufacturing firms while short term and long-term portfolio investment have negative relationship with net book value of the quoted manufacturing firms while the probability coefficient of the variables informed us that the independent variables are statistically not significant. From the findings, the study conclude that investment policy affect significantly the net book value of the quoted manufacturing firms. It recommends that proper investment analysis should be carried out in appraising short term investment to enhance value of manufacturing firms. There is need for management to integrate the objectives of long term investment with the value objective of Nigeria manufacturing firms.