High-pass NGD characterization of resistive-inductive network based low-frequency circuit

Author(s):  
Mathieu Guerin ◽  
Fayu Wan ◽  
Konstantin Gorshkov ◽  
Xiaoyu Huang ◽  
Bogdana Tishchuk ◽  
...  

Purpose The purpose of this paper is to provide the high-pass (HP) negative group delay (NGD) circuit based (RL) network. Synthesis and experimental investigation of HP-NGD circuit are developed. Design/methodology/approach The research work methodology is organized in three phases. The definition of the HP-NGD ideal specifications is introduced. The synthesis method allowing to determine the RL elements is developed. The validation results are discussed with comparison between the calculated model, simulation and measurement. Findings This paper shows a validation of the HP-NGD theory with responses confirming NGD optimal frequency, value and attenuation of about (9 kHz, −1.12 µs, −1.64 dB) and (21 kHz, −0.92 µs, −4.81 dB) are measured. The tested circuits have experimented NGD cut-off frequencies around 5 and 11.7 kHz. Research limitations/implications The validity of the HP-NGD topology depends on the coil self-inductance resonance. The HP-NGD effect is susceptible to be penalized by the parasitic elements of the self. Practical implications The NGD circuit is usefully exploited in the electronic and communication system to reduce the undesired delay effect context. The NGD can be used to compensate the delay in any electronic devices and system. Social implications Applications based on the NGD technology will be helpful in the communication, transportation and security research fields by reducing the delay inherent to any electronic circuit. Originality/value The originality of the paper concerns the synthesis formulations of the RL elements in function of the expected HP-NGD optimal frequency, value and attenuation. In addition, an original measurement technique of HP-NGD is also introduced.

2019 ◽  
Vol 37 (1) ◽  
pp. 67-80 ◽  
Author(s):  
Muhammad Farooq ◽  
Hikmat Ullah Khan ◽  
Tassawar Iqbal ◽  
Saqib Iqbal

Purpose Bibliometrics is one of the research fields in library and information science that deals with the analysis of academic entities. In this regard, to gauge the productivity and popularity of authors, publication counts and citation counts are common bibliometric measures. Similarly, the significance of a journal is measured using another bibliometric measure, impact factor. However, scarce attention has been paid to find the impact and productivity of conferences using these bibliometric measures. Moreover, the application of the existing techniques rarely finds the impact of conferences in a distinctive manner. The purpose of this paper is to propose and compare the DS-index with existing bibliometric indices, such as h-index, g-index and R-index, to study and rank conferences distinctively based on their significance. Design/methodology/approach The DS-index is applied to the self-developed large DBLP data set having publication data over 50 years covering more than 10,000 conferences. Findings The empirical results of the proposed index are compared with the existing indices using the standard performance evaluation measures. The results confirm that the DS-index performs better than other indices in ranking the conferences in a distinctive manner. Originality/value Scarce attention is paid to rank conferences in distinctive manner using bibliometric measures. In addition, exploiting the DS-index to assign unique ranks to the different conferences makes this research work novel.


2021 ◽  
Vol 11 (15) ◽  
pp. 6688
Author(s):  
Jesús Romero Leguina ◽  
Ángel Cuevas Rumin ◽  
Rubén Cuevas Rumin

The goal of digital marketing is to connect advertisers with users that are interested in their products. This means serving ads to users, and it could lead to a user receiving hundreds of impressions of the same ad. Consequently, advertisers can define a maximum threshold to the number of impressions a user can receive, referred to as Frequency Cap. However, low frequency caps mean many users are not engaging with the advertiser. By contrast, with high frequency caps, users may receive many ads leading to annoyance and wasting budget. We build a robust and reliable methodology to define the number of ads that should be delivered to different users to maximize the ROAS and reduce the possibility that users get annoyed with the ads’ brand. The methodology uses a novel technique to find the optimal frequency capping based on the number of non-clicked impressions rather than the traditional number of received impressions. This methodology is validated using simulations and large-scale datasets obtained from real ad campaigns data. To sum up, our work proves that it is feasible to address the frequency capping optimization as a business problem, and we provide a framework that can be used to configure efficient frequency capping values.


2014 ◽  
Vol 26 (2) ◽  
pp. 87-95 ◽  
Author(s):  
J. Mittal ◽  
K.L. Lin

Purpose – This paper aims to compare the reflow and Zn diffusion behaviors in Sn-Zn and Sn-8.5Zn-0.5Ag-0.01Al-0.1Ga (5E) solders during soldering on a Ni/Cu substrate under infrared (IR) reflow. The study proposes a model on the effect of various elements particularly Zn diffusion behavior in the solders on the formation of intermetallic compounds (IMCs). Design/methodology/approach – The melting activities of two solders near their melting points on copper substrates are visualized in an IR reflow furnace. Reflowed solder joints were analyzed using scanning electron microscope and energy dispersive X-ray spectroscopy. Findings – Reflow behaviors of the solders are similar. During melting, solder balls are first merged into each other and then reflow on the substrate from top to bottom. Both solders show a reduced amount of Zn in the solder. Theoretical calculations demonstrate a higher Zn diffusion in the 5E solder; however, the amount of Zn actually observed at the solder/substrate interface is lower than Sn-9Zn solder due to the formation of ZnAg3 in the solder. A thinner IMC layer is formed at the interface in the 5E solder than the Sn-Zn solder. Research limitations/implications – The present work compares the 5E solder only with Sn-Zn solder. Additional research work may be required to compare 5E solder with other solders like Sn-Ag, SnAgCu, etc. to further establish its practical applications. Practical implications – The study ascertains the advantages of 5E solder over Sn-Zn solder for all practical applications. Originality/value – The significance of this paper is the understanding of the relation between reflow behavior of solders and reactivity of different elements in the solder alloys and substrate to form various IMCs and their influence on the formation of IMC layer at solder/substrate interface. Emphasis is provided for the diffusion behavior of Zn during reflow and respective reaction mechanisms.


2018 ◽  
Vol 2 (3) ◽  
pp. 247-258
Author(s):  
Zhishuo Liu ◽  
Qianhui Shen ◽  
Jingmiao Ma ◽  
Ziqi Dong

Purpose This paper aims to extract the comment targets in Chinese online shopping platform. Design/methodology/approach The authors first collect the comment texts, word segmentation, part-of-speech (POS) tagging and extracted feature words twice. Then they cluster the evaluation sentence and find the association rules between the evaluation words and the evaluation object. At the same time, they establish the association rule table. Finally, the authors can mine the evaluation object of comment sentence according to the evaluation word and the association rule table. At last, they obtain comment data from Taobao and demonstrate that the method proposed in this paper is effective by experiment. Findings The extracting comment target method the authors proposed in this paper is effective. Research limitations/implications First, the study object of extracting implicit features is review clauses, and not considering the context information, which may affect the accuracy of the feature excavation to a certain degree. Second, when extracting feature words, the low-frequency feature words are not considered, but some low-frequency feature words also contain effective information. Practical implications Because of the mass online reviews data, reading every comment one by one is impossible. Therefore, it is important that research on handling product comments and present useful or interest comments for clients. Originality/value The extracting comment target method the authors proposed in this paper is effective.


2014 ◽  
Vol 11 (2) ◽  
pp. 176-191 ◽  
Author(s):  
Rajneesh Mahajan ◽  
Suresh Garg ◽  
P.B. Sharma

Purpose – The purpose of this paper is to investigate perspective in explaining how global food safety can be created through stringent implementation of Codex and World Trade Organization (WTOs) Sanitary and Phytosanitary food safety regulations and suggests the appropriate food safety system for India. Design/methodology/approach – The study has been deployed a survey questionnaire using a sample of Indian Processed food sector. In order to collect data 1,000 supply chain professional were contacted for seeking their consent to be part of the survey. Whereas total responses collected were 252 from Delhi and NCR, with response rate 25.2 percent. The data collected was empirical tested using descriptive statistics, correlation analysis, regression and ANOVA. Findings – The results and discussions indicate that all the global food safety norms laid down by WTO such as goods manufacturing practices, good hygienic practice, hazard analysis critical control point, has been developed to embody principles of safe food processing sector globally. India has also developed their food safety norms as per laid down principles by WTO. Originality/value – The present research work makes an important contribution to the body of literature on global food safety. The paper has important implications for the processed food sector since it tries to bring out practices which would help in successful implementation of global food safety standards. It is useful for academic food research as well as for processed food corporate.


2017 ◽  
Vol 8 (1) ◽  
pp. 109-130 ◽  
Author(s):  
Jasim Aldairi ◽  
M.K. Khan ◽  
J. Eduardo Munive-Hernandez

Purpose This paper aims to develop a knowledge-based (KB) system for Lean Six Sigma (LSS) maintenance in environmentally sustainable buildings (Lean6-SBM). Design/methodology/approach The Lean6-SBM conceptual framework has been developed using the rule base approach of KB system and joint integration with gauge absence prerequisites (GAP) technique. A comprehensive literature review is given for the main pillars of the framework with a typical output of GAP analysis. Findings Implementation of LSS in the sustainable building maintenance context requires a pre-assessment of the organisation’s capabilities. A conceptual framework with a design structure is proposed to tackle this issue with the provision of an enhancing strategic and operational decision-making hierarchy. Research limitations/implications Future research work might consider validating this framework in other type of industries. Practical implications Maintenance activities in environmentally sustainable buildings must take prodigious standards into consideration, and, therefore, a robust quality assurance measure has to be integrated. Originality/value The significance of this research is to present a novel use of hybrid KB/GAP methodologies to develop a Lean6-SBM system. The originality and novelty of this approach will assist in identifying quality perspectives while implementing different maintenance strategies in the sustainable building context.


2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
Vijaya Kumar Name ◽  
C. S. Vanaja

Background. The aim of this study was to investigate the individual effects of envelope enhancement and high-pass filtering (500 Hz) on word identification scores in quiet for individuals with Auditory Neuropathy. Method. Twelve individuals with Auditory Neuropathy (six males and six females) with ages ranging from 12 to 40 years participated in the study. Word identification was assessed using bi-syllabic words in each of three speech processing conditions: unprocessed, envelope-enhanced, and high-pass filtered. All signal processing was carried out using MATLAB-7. Results. Word identification scores showed a mean improvement of 18% with envelope enhanced versus unprocessed speech. No significant improvement was observed with high-pass filtered versus unprocessed speech. Conclusion. These results suggest that the compression/expansion signal processing strategy enhances speech identification scores—at least for mild and moderately impaired individuals with AN. In contrast, simple high-pass filtering (i.e., eliminating the low-frequency content of the signal) does not improve speech perception in quiet for individuals with Auditory Neuropathy.


2013 ◽  
Vol 10 (4) ◽  
pp. 252-269 ◽  
Author(s):  
Antigoni Parmaxi ◽  
Panayiotis Zaphiris ◽  
Salomi Papadima-Sophocleous ◽  
Andri Ioannou

Purpose – The purpose of this study is to chart the development in computer-assisted language learning (CALL), by building a map of existing research work in the field. Based on a corpus of 163 manuscripts, published between January 2009 and September 2010 in four major journals devoted to CALL, it sets out to describe the range of topics covered under the umbrella of CALL and provide a holistic view of the field. Design/methodology/approach – The approach adopted in this research includes: development of the 2009-2010 CALL corpus; literature overview and initial coding scheme development; refinement of the initial coding scheme with the help of a focus group and construction of the CALL map version 1.0; refinement of the CALL map version 1.0 following a systematic approach of content analysis and development of the CALL map version 2.0; evaluation of the proposed structure and inclusiveness of all categories in the CALL map version 2.0 using card sorting technique; and finally development of the CALL map version 3.0. Findings – The research trends in the categories of the CALL map are discussed, as well as possible future directions in the field. Originality/value – This paper provides a holistic view of the field of CALL guiding both junior CALL researchers to place themselves in the field, and policy and decision makers who attempt to evaluate the current and future scholar activity in the field. Finally, it caters for more experienced researchers to focus on certain underinvestigated domains.


2016 ◽  
Vol 8 (5) ◽  
pp. 593-605 ◽  
Author(s):  
Daniele Vieira do Nascimento

Purpose The purpose of this paper is to provide an overview of the links between climate finance and tourism adaptation development. Besides increasing adaptation and mitigation efforts to limit greenhouse gas emissions, climate change remains a major challenge in the twenty-first century and beyond especially for tourism which is highly climate sensitive. Hence, it is necessary for tourism to adapt to survive. The aim of the study is to provide a systematic overview of the topic to offer a foundation for better understanding different ways of integrating climate finance initiatives with tourism. Design/methodology/approach The research focused on the top-ranked, peer reviewed journals of each of the two selected research fields. To address this topic, an in-depth systematic literature review in the fields of climate change finance and tourism adaptation development was conducted. Furthermore, because it is a relatively new research topic, conference proceedings were also explored. To guarantee wide coverage of the literature, a query of the following scholarly databases was considered: Elsevier, ScienceDirect and Web of Science. Findings Based on the analyses of the literature available on the topic, the paper highlights the main research trends and conclusions. It is argued that there is imbalance of knowledge on climate change finance as it relates to tourism. To date, there have been relatively few published articles on this topic in the context of tourism. Based on the findings, promising areas for future research were identified, and in particular for small island communities and recommendations for future research are outlined. Research limitations/implications The paper is limited by the scope of the literature review accessed by the researcher. The results of this review may vary according to the databases used. Originality/value Currently, there is no extensive review of articles on climate finance and tourism adaptation. This paper aims at reviewing climate finance studies published in English language to explore knowledge gaps in tourism adaptation. Sets of themes being advanced are also highlighted. Recommendations for future research are provided.


2016 ◽  
Vol 27 (1) ◽  
pp. 15-21 ◽  
Author(s):  
M Kumaresan

Purpose – The purpose of this paper is to extract the eco-friendly natural dye obtained from the flower of Spathodea campanulata and apply on silk fabric using combination of mordants. The fastness properties of the flower of Spathodea campanulata dyed silk fabric have been studied using different combination (1:3, 1:1 and 3:1) of various mordants, such as myrobolan: nickel sulphate, myrobolan: aluminium sulphate, myrobolan: potassium dichromate, myrobolan: ferrous sulphate and myrobolan: stannous chloride. The wash, rub, light and perspiration fastness of the dyed samples have been evaluated. Design/methodology/approach – For dyeing there are three methods are used. They are Pre mordanting, Simultaneous mordanting and Post mordanting methods. Dyed silk materials are tested by using wash fastness, rub fastness, light and perspiration fastness methods. Findings – It is found that Spathodea campanulata dye can be successfully used for the dyeing of silk to obtain a wide range colours by using various combinations of mordants. With regards to colour fastness, test samples exhibit excellent fastness to washing, rubbing, except for pre-mordanting using myrobolan: potassium dichromate combination; and good to excellent fastness to perspiration in both acidic and alkaline media. Originality/value – Availability of literature related to this work is not available. The study of combination of mordants of this natural dye on silk is a new research work and the large scale preparation is definitely very useful to the society.


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