Authors:Narongrit Sombatsompop, T. Markpin, and N. Premkamolnetr
This article introduces a new modified method for calculating the impact factor of journals based on the current ISI practice in generating journal impact factor values. The impact factor value for a journal calculated by the proposed method, the so-called Cited Half-Life Impact Factor (CHAL) method, which is based on the ratio of the number of current year citations of articles from the previous X years to that of articles published in the previous X years, the X value being equal to the value of the cited half-life of the journal in the current year. Thirty-four journals in the Polymer Science Category from the ISI Subject Heading Categories were selected and examined. Total citations, impact factors and cited half-life of the 34 journals during the last five years (1997-2001) were retrieved from the ISI Journal Citation Reports and were used as the data source for the calculations in this work, the impact factor values from ISI and CHAL methods then being compared. The positions of the journals ranked by impact factors obtained from the ISI method were different from those from the CHAL method. It was concluded that the CHAL method was more suitable for calculating the impact factor of the journals than the existing ISI method.
Authors:N. Sombatsompop, P. Ratchatahirun, V. Surathanasakul, N. Premkamolnetr, and T. Markpin
This article aimed to report Journal Impact Factor (J-IF) and Journal Immediacy Index (J-II) of 68 Thai academic journals
during the past five years (from 1996 to 2000) using the calculation method given by the Institute for Scientific Information
(ISI). This was the first time that the citation indexes of Thai academic journals were established. With respect to the journal
impact factor, the results showed that only six journals have been cited continuously during the past five years, this being
8.8% of the total journal number selected in this work. It was also noticeable that articles published in longer journal age
tended to have greater opportunity to be cited and higher journal impact factor. The average impact factor of the 68 journals
was relatively low, this being of 0.069, suggesting that the possibility of an article published in a national journal to
be cited was only 6.9%. In terms of the immediacy index, it was found that the average immediacy index value was 0.063, which
was again very low. No significant relationship between the journal age and the immediacy index could be observed. 47% of
the journals have never been able to produce the immediacy index in the past five years, suggesting that articles in the Thai
academic journals were hardly cited within the same years they were published.
Authors:N. Sombatsompop, T. Markpin, T. Buranathiti, P. Ratchatahirun, T. Metheenukul, N. Premkamolnetr, and W. Yochai
This article offers information on the characteristics and number of materials research articles indexed in the Science Citation
Index (SCI) database in the year of 2004. 22,843 articles in full-text forms from 169 journals from the materials field (which
included ceramics, metallurgy, and polymer journals) were retrieved from the SCI database and exported to EndNote software.
The retrieved articles were carefully analyzed by eight scientists and experts in those subfields and categorized using SPSS
into eight different categories, being (1) New materials, (2) Materials characterizations, (3) Materials improvement, (4)
New process and/or process improvement, (5) Mathematical and theoretical models and/or computer simulations, (6) Novel and
comprehensive explanations, (7) Testing conditions, and (8) Comparative studies, whose definitions were clearly indicated.
The results were then considered in terms of the percentage of the number of articles in each materials subfield, country
of corresponding author, and number of authors.
The overall results suggested that, most materials articles published in 2004 were focused on new process and process improvement
(27%), while materials characterizations (23%) and testing conditions (12%) took the 2nd and 3rd places, especially for the
ceramics and polymer articles. The highest numbers of articles in the ceramics and polymer subfields were focused on new processes
and/or process improvement, and those for the metallurgy subfield were on materials characterization. In the SCI database,
the largest number of materials articles was authored from Asian scientists although the majority of the materials journals
were run by editors from Europe in North America/Canada continents. There was no coherent relationship between the authors’
and editors’ affiliations. China, Japan and the United States of America (USA) were shown to be the top three countries which
had the highest publication numbers in the materials field. Japan had the highest publication numbers in the ceramics subfield
while China possessed most publications in polymer and metallurgy subfields. However, when considering the journal impact
factors, the leading positions of the countries changed. The results from this work could assist materials scientists to select
suitable international journals in relevant association with the contents of their to-publish works. Finally, it was noted
that most material research articles were written by 3–4 authorships.
Authors:T. Buranathiti, N. Premkamolnetr, T. Markpin, P. Ratchatahirun, W. Yochai, and N. Sombatsompop
This article introduced two sampling methods, including Directly Random Sampling (DRS) and Redistributed Random Sampling (RRS)
methods for categorization of a large number of research articles retrieved from metallurgy and polymer subfields from the
Science Citation Index (SCI) database. The accuracy of the proposed sampling methods was considered in association by comparing
with reference results previously obtained by Fully Retrieving Sampling (FRS) method, which involved analyzing the contents
and categories of all articles from the database. The results suggested that RRS and DRS methods were appropriate, efficient
and reasonably accurate for categorization of relatively large volume of research articles. RRS method was highly recommended,
especially when the contents of sample articles was unevenly distributed. By DRS and RRS methods, only about 6.3% of total
articles were required for obtaining similar results as those given by FRS method. The percentage Expected Worst Errors (EWE)
from DRS and RRS methods were observed to range from 1.0 to 5.5%. The EWE value could be reduced by increasing the sample
Authors:Narongrit Sombatsompop, T. Markpin, E. Wimolmala, P. Ratchatahirun, N. Premkamolnetr, B. Boonradsamee, and W. Yochai
This article investigated contributions of natural rubber (NR) research through research articles and patents in Science Citation
Index Expanded (SCI-Expanded) and SCOPUS databases and related the results with productivity-export volumes during 2002–2006.
1,771 research papers and 5,686 patents on “natural rubber” were retrieved from the databases. The results revealed that the
top five countries produced the NR raw material by the order of productivity volumes were Thailand, Indonesia, Malaysia, Vietnam
and China whereas those produced the synthetic rubber were the United States, China, Japan, Russia and Germany. Among the
top three countries for NR production, Malaysia became a NR producer for its own use, whereas Thailand and Indonesia still
had higher export volumes. Research articles and patents on natural rubber had contribution shares of about 20.9% and 47.5%
of all rubber publications, respectively. The patents on natural rubber were found to increase with time while the research
articles remained unchanged. Journal of Applied Polymer Science was the most preferable for publishing the research papers
on rubbers. Eight countries ranked in the top countries for contributing the research articles on natural rubber were the
United States, India, Malaysia, France, Germany, Thailand, Japan and China, similar country distributions being also found
for research articles on synthetic styrene-butadiene rubber except for Thailand and Malaysia. No linear relationship between
the productivity-export volume and research publication number was observed, but the results implied that the growth rate
for commercializing the rubber was greater than that for research and development of natural rubber. Most NR research works
focused on neat NR, which was contributed the most by USA while NR blend and NR composite papers were mainly published by
Authors:T. Markpin, B. Boonradsamee, K. Ruksinsut, W. Yochai, N. Premkamolnetr, P. Ratchatahirun, and N. Sombatsompop
This article proposed a new index, so-called “Article-Count Impact Factor” (ACIF) for evaluating journal quality in light
of citation behaviour in comparison with the ISI journal impact factors. The ACIF index was the ratio of the number of articles
that were cited in the current year to the source items published in that journal during the previous two years. In this work,
we used 171 journal titles in materials categories published in the years of 2001–2004 in international journals indexed in
the Science Citation Index Expanded (SCI) database as data source. It was found that ACIF index could be used as an alternative
tool in assessing the journal quality, particularly in the case where the assessed journals had the same (equal or similar)
JIF values. The experimental results suggested that the higher the ACIF value, the more the number of articles being cited.
The changes in ACIF values were more dependent on the JIF values rather than the total number of articles. Polymer Science
had the greatest ACIF values, suggesting that the articles in Polymer Science had greater “citation per article” than those in Metallurgical Engineering and Ceramics. It was also suggested that in order to increase a JIF value of 1.000,
Ceramics category required more articles to be cited as compared to Metallurgical Engineering and Polymer Science categories.