Biochemistry has been broadly defined as “chemistry of molecules included or related to living systems”, but is becoming increasingly hard to be distinguished from other related fields. Targets of its studies evolve rapidly; some newly emerge, disappear, combine, or resurface themselves with a fresh viewpoint. Methodologies for biochemistry have been extremely diversified, thanks particularly to those adopted from molecular biology, synthetic chemistry, and biophysics. Therefore, this paper adopts topic modeling, a text mining technique, to identify the research topics in the field of biochemistry over the past twenty years and quantitatively analyze the changes in its trends. The results of the topic modeling analysis obtained through this study will provide a helpful tool for researchers, journal editors, publishers, and funding agencies to understand the connections among the diverse sub-fields in biochemical research and even see how the research topics branch out and integrate with other fields.

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Subway stations have been proliferating underneath cosmopolitan metropolises with subway lines forming complex webs connected in strategic transfer stations. The efficiency of the subway system thus heavily weighs on the efficiency at these transfer stations. However, few studies have been conducted on transfer efficiency at transfer stations due to the complexities involved. As the first study of its kind in the subway context, we analyze the transfer efficiency of the subway transfer stations in Seoul, one of the megacities in the world, and demonstrate how transfer efficiency can be analyzed using bootstrap-based DEA technique. Based on the results, we discuss the reasons behind the inefficiency of subway transfer stations and possible ways to improve them into efficient decision-making units.

Abstract:In light of the growing importance of data network quality in the wireless industry, this study analyzes and compares efficiencies in management, service quality, network quality, and market in the 4G Long Term Evolution (LTE) wireless industry. For this purpose, a bootstrap data envelopment analysis (DEA) model using representative U.S. wireless carriers as decision making units (DMUs) was designed and conducted, with further verification through the Mann-Whitney U and Wilcoxon W test, to examine the differences in efficiency distribution. The results indicate that, in terms of efficiency distribution, network quality efficiency and market efficiency belongs to the same group as that which has high management efficiency. Based on these results, this paper suggests implications and strategic guidelines for wireless carriers for improvement in management efficiency.

This research investigates the impact of COVID-19 on hotel productivity change using the Malmquist Productivity Index (MPI). For 26 U.S. hotel brands, productivity changes over 10 quarters from the first quarter of 2018 to the second quarter of 2020 were analyzed. After the COVID-19 outbreak, the investigated hotels’ productivity deteriorated. Decomposition revealed that, whereas technical efficiency change (EC) improved, technological change (TC) regressed, resulting in deterioration of the MPI. The investigated hotels’ EC-related practices included enhanced cleaning operations, partnering with a hygiene brand, cutting the workforce, and pay cuts. Practices related to TC included the adoption of new hygiene technology and setting a new standard at the organizational level through the formation of a global council and accreditation related to disinfection and hygiene. Our results show that though U.S. hotels are trying to improve their productivity by efficiently utilizing resources, frontier technology’s regress is decreasing productivity. Our results support the importance of investment in technology for productivity management. This research provides empirical evidence for the need for hotels to pursue technological advances to overcome the pandemic.