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This paper focuses on the differences in domain intellectual structure discovery between author bibliographic coupling analysis (ABCA) and author co-citation analysis (ACA) considering all authors. The purpose of this study is to examine whether and in what ways these two all-author network approaches yield different results.

The sample was collected from the database of Web of Science, including all articles published in Scientometrics and Journal of Informetrics from 2011 to 2020. First, 100 representative authors were selected from each set, and ABCA matrices and ACA matrices were constructed. Second, factor analysis was carried out on the matrices, to detect the intellectual structure of scientometrics and informetrics.

The intellectual structures identified by ABCA and ACA are similar overall, but the results differ somewhat when it comes to specific structures. The ABCA is more sensitive to some highly collaborative research teams and presents a clearer picture of current intellectual structures and trends while ACA seems to have some advantages in representing the more traditional and proven research topics in the field. The combined use of ABCA and ACA allows for a more comprehensive and specific intellectual structure of research fields.

This paper compares the performance of ABCA and ACA detecting the intellectual structure of the domain from the perspective of all authors, revealing the intellectual structure of scientometrics and informetrics comprehensively.

The peer review history for this article is available at: https://publons.com/publon/10.1108/OIR-12-2020-0540.

The purpose of this paper is to present a novel n‐buried‐PSOI sandwiched radio frequencies (RF) power lateral diffused metal‐oxide semiconductor (LDMOS) and analyze its output characteristics.

The small‐signal equivalent circuit for RF power LDMOS method is used to analyze the proposed structure and the simulation and optimization are done using the computer‐aided design tools.

This improved structure is clearly decreasing drain‐substrate parasitic capacitance. At 1 dB compression point, its output power, the power‐added efficiency and the breakdown voltage are higher than that of the conventional LDMOS.

This paper puts forward a novel n‐buried‐PSOI sandwiched structure of RF power LDMOS. The analysis indicates that the output characteristics of this device are a great improvement on the conventional LDMOS and the n‐buried‐PSOI, RF power LDMOS proposed by earlier authors.

The purpose of this paper is to present a novel n‐buried partial silicon‐on‐nothing (SON) structure of radio frequencies (RF) power lateral double‐diffused metal‐oxide‐semiconductor (LDMOS) and analyze its RF characteristics.

The small‐signal equivalent circuit for RF power LDMOS method is used to analyze the proposed structure and the simulation and optimization are done using 2D simulator MEDICI.

This improved structure is clearly decreasing drain‐substrate parasitic capacitance. At 1 dB compression point, its output power, the power‐added efficiency and the breakdown voltage is higher than that of the conventional LDMOS.

This paper usefully shows how SON having low‐dielectric constant can reduce the horizontal drain field and the drain‐substrate capacitance, and increase the breakdown voltage as a result.

The purpose of this study is to identify attitude differences between smokers and non‐smokers regarding smoking in restaurants and existing smoking by‐laws. The findings can assist restaurant managers to resolve the dilemma of in‐restaurant smoking. Qualitative research methods were used to capture the holistic and meaningful characteristics of real‐life events. Three different data collection techniques were employed for methodological triangulation. Content analysis was applied to the data, collected through participant observations, focus group interviews, and in‐depth interviews. To account for the relationship between a theoretical perspective and certain messages, the categories used in the content analysis were determined by both induction and deduction. The findings enhance the understanding smoking and non‐smoking customers’ thoughts, feelings, and actions in restaurants, and clarifying the resulting challenges for restaurant managers.

As the solution to improve fatigue life and mechanical reliability of packaging structure, the material selection in PCB stack-up and partitioning design on PCB to eliminate the electromagnetic interference by keeping all circuit functions separate are suggested to be optimized from the mechanical stress point of view.

The present paper investigated the effect of RO4350B and RT5880 printed circuit board (PCB) laminates on fatigue life of the QFN (quad flat no-lead) packaging structure for high-frequency applications. During accelerated thermal cycling between −50 °C and 100 °C, the mismatched coefficients of thermal expansion (CTE) between packaging and PCB materials, initial PCB warping deformation and locally concentrated stress states significantly affected the fatigue life of the packaging structure. The intermetallics layer and mechanical strength of solder joints were examined to ensure the satisfactorily soldering quality prior to the thermal cycling process. The failure mechanism was investigated by the metallographic observations using a scanning electron microscope.

Typical fatigue behavior was revealed by grain coarsening due to cyclic stress, while at critical locations of packaging structures, the crack propagations were confirmed to be accompanied with coarsened grains by dye penetration tests. It is confirmed that the cyclic stress induced fatigue deformation is dominant in the deformation history of both PCB laminates. Due to the greater CTE differences in the RT5880 PCB laminate with those of the packaging materials, the thermally induced strains among different layered materials were more mismatched and led to the initiation and propagation of fatigue cracks in solder joints subjected to more severe stress states.

In addition to the electrical insulation and thermal dissipation, electronic packaging structures play a key role in mechanical connections between IC chips and PCB.

The purpose of this paper is to examine the writing development of Hong Kong kindergarten students over 12 months. They attended 18 kindergartens territory-wide and were followed from June 2002 to June 2003 for the collection of three waves of teacher-rated data at six-month intervals.

First, the construct validity of the translated and culturally adapted version of Morrow’s (2012) checklist which assesses writing development was confirmed, considering that the students attended Hong Kong kindergartens who wrote in the Chinese language. The multilevel analysis, which employed corrected measures captured through Wolfe and Chiu’s (1999a, 1999b) five-step Rasch scaling method for a common frame of reference, estimated the effects of the factors, namely, student age, gender, class level and schools.

The children’s progress over the second six months was also apparently much smaller than the first SIX months for this cohort. The dramatic slow-down in the second six-month period for both cohorts might be partly attributed to the peculiar arrangement of schooling at that time.

The recommendation from this study is that random sampling and student test scores on writing need to be taken for the identification of the general trend of young children’s writing development in Hong Kong, as well as other Chinese communities alike.

The profile of the student’s emergent writing development at each six-month follow-up and over the 12 months was explored. Differences between the groups based on age, gender, class level and school in terms of student writing development on average were statistically significant.

Vapor phase soldering (VPS), also known as condense soldering, is capable of improving the mechanical reliability of solder joints in electronic packaging structures. The paper aims to discuss this issue.

In the present study, VPS is utilized to assemble two typical packaging types (i.e. ceramic column grid array (CCGA) and BGA) for electronic devices with lead-containing and lead-free solders. By applying the peak soldering temperatures of 215°C and 235°C with and without vacuum condition, the void formation and intermetallic compound (IMC) thickness are compared for different packaging structures with lead-containing and lead-free solder alloys.

It is found that at the soldering temperature of 215°C, CCGA under a vacuum condition has fewer voids but BGA without vacuum environment has fewer voids despite of the existence of lead in solder alloy. In light of contradictory phenomenon about void formation at 215°C, a similar CCGA device is soldered via VPS at the temperature of 235°C. Compared with the size of voids formed at 215°C, no obvious void is found for CCGA with vacuum at the soldering temperature of 235°C. No matter what soldering temperature and vacuum condition are applied, the IMC thickness of CCGA and BGA can satisfy the requirement of 1.0–3.0 µm. Therefore, it can be concluded that the soldering temperature of 235°C in vacuum is the optimal VPS condition for void elimination. In addition, shear tests at the rate of 10 mm/min are performed to examine the load resistance and potential failure mode. In terms of failure mode observed in shear tests, interfacial shear failure occurs between PCB and bulk solder and also within bulk solder for CCGA soldered at temperatures of 215°C and 235°C. This means that an acceptable thicker IMC thickness between CCGA solder and device provides greater interfacial strength between CCGA and device.

Due to its high I/O capacity and satisfactory reliability in electrical and thermal performance, CCGA electronic devices have been widely adopted in the military and aerospace fields. In the present study, the authors utilized VPS to assemble a typical type of CCGA with the control package of conventional BGA to investigate the relation between essential condition (i.e. soldering temperature and vacuum) to void formation.

Kenya basks of a vibrant digital financial sector from her mobile and digital financial services that have led to financial inclusions. On the flip side of it, the Kenyan digital loans sector is facing ethical scrutiny from all and sundry. Issues that are arising include a customer base being trapped in the debt trap, inflated pricing model, high interest rates, and short-term loan tenures. The sector is shrouded in poor transparency and many consumer rights infringement. Undeniably, providers inadvertently breach consumers' right to privacy and tend to promote ‘push loans’ with unsolicited messages to the vulnerable. Additionally, the use of Artificial Intelligence (AI) in determining the suitability of loan applicants via algorithms is seen to be intrusive. With consumer data being mined from the mobile phone, data utilisation, mobile payment usage, airtime usage without users' express consent, it renders the sector an unethical jungle for hunting consumers. Furthermore, consumers who by default end up receiving aggressive uncouth and unprofessional treatment in a bid to recover the unpaid loans. New Product Development (NPD) should, therefore, listen to the consumer's voice for ethical concerns to be reflected in the final product. Thus, marketers should endeavour to give ethical dimensions in NPD a measurable attribute by constantly reviewing it. This chapter examines the ethical implications of developing digital loans in Kenya.

The purpose of this paper is to acquire doubly variable precision‐based knowledge rules from incomplete decision tables (IDTs) in the framework of pansystems methodology. It suggests a new variable precision limited tolerance – a special pansystems relation – rough set model with precision inclusion and a reduct procedure in which it overcomes the non‐monotony in forming tolerance classes when reducing an attribute from attribute set.

Through introducing variable precision and limited tolerance relation in IDT, it constructs symmetric binary relation, dissimilar to non‐symmetric relation proposed by others, and then forms tolerance classes. It proposes a new reduction procedure with absolute value calculation to avoid tolerance classes being non‐monotone. Using variable inclusion, it obtains lower and upper approximations with noises.

Tolerance classes are not monotone with the reduction of attribute from attribute set in the proposed variable precision and limited tolerance relation, but it remains symmetry. Proposed reduction procedure with absolute value calculation is a new approach in adjudging whether a reduct equals to the original whole attribute set within a error range or not.

Using variable precision and limited rough set model with variable inclusion to mine deep knowledge from IDT is a paradise in knowledge discovery in dealing with non‐determinative and vague problems.

The formation of symmetric tolerance relation is natural. The reduction procedure with absolute value calculation is new and not similar to those existed in literatures.

Based on the perspectives of social capital, image motivation and motivation affordances, this paper explores the direct and moderation effects of different kinds of motivations (i.e. relationship-based motivation, community-based motivation and individual-based motivation) on users' continuous knowledge contributions in social question and answer (Q&A) communities.

The authors collect the panel data of 10,193 users from a popular social Q&A community in China. Then, a negative binomial regression model is adopted to analyze the collected data.

The paper demonstrates that social learning, peer recognition and knowledge seeking positively affect users' continuous contribution behaviors. However, the results also show that social exposure has the opposite effect. In addition, self-presentation is found to moderate the influence of social factors on users' continuous use behaviors, while the moderation effect of motivation affordances has no significance.

First, this study develops a comprehensive motivation framework that helps gain deeper insights into the underlying mechanism of knowledge contribution in social Q&A communities. Second, this study conducts panel data analysis to capture the impacts of motivations over time, rather than intentions at a fixed time point. Third, the findings can help operators of social Q&A communities to optimize community norms and incentive mechanisms.