Discovering and assessing fields of expertise in nanomedicine: a patent co-citation network perspective

Discovering and assessing fields of expertise in emerging technologies from patent data is not straightforward. First, patent classification in an emerging technology being far from complete, the definitions of the various applications of its inventions are embedded within communities of practice. Because patents must contain full record of prior art, co-citation networks can, in theory, be used to identify and delineate the inventive effort of these communities of practice. However, the use patent citations for the purpose of measuring technological relatedness is not obvious because they can be added by examiners. Second, the assessment of the development stage of emerging industries has been mostly done through simple patent counts. Because patents are not all valuable, a better way of evaluating an industry’s stage of development would be to use multiple patent quality metrics as well as economic activity agglomeration indicators. The purpose of this article is to validate the use of (1) patent citations as indicators of technological relatedness, and (2) multiple indicators for assessing an industry’s development stage. Greedy modularity optimization of the ‘Canadian-made’ nanotechnology patent co-citation network shows that patent citations can effectively be used as indicators of technological relatedness. Furthermore, the use of multiple patent quality and economic agglomeration indicators offers better assessment and forecasting potential than simple patent counts.     

Analyzing the value of technology based on the differences of patent citations between applicants and examiners

Patent applicants and examiners do not always have the same point of view when conducting a prior-art search. Although several studies have suggested differences between citations by applicants and examiners, the data and range of empirical studies are too incomplete to generalize the characteristics of relationships between citation types and the value of a technology or invention. To overcome this limitation, it is crucial to compare citations by applicants and by examiners in depth, with diverse perspectives and data, to determine the value of patent information for technological innovation. Thus, this paper suggests that the differences in the composition of technical information and patent quality in patent-level investigations as well as the locus of the knowledge source and knowledge recentness in knowledge-level investigations according to patent citation type (by applicants and examiners) reflect Pavitt’s perspective on the nature, impact, and source of technological innovation. We found that the quality of patents cited by applicants is higher than that of those by examiners in four industries, excluding a supplier-dominated industry. The citation types are related to the locus of the knowledge source in four industries, excluding the supplier-dominated industry. In particular, the patents cited by examiners tended to be more recently issued in all sectoral fields. This research contributes to confirming the technological value of patents based on the citation behaviors of applicants and examiners through empirical analysis. The results can be utilized to investigate signals or noise in technological innovation and improve processes or systems of patent examination. In addition, it can help applicants conduct more thorough prior-art searches by comprehending the examiner’s perspective toward citations to increase the probability of patent registration.     

Large firms and the science-technology interface Patents,patent citations,and scientific output of multinational corporations in thin films

Firms operating in science-based technological fields reflect some of the complexities of the science-technology interaction. The present study attempts to investigate these interactions by analyzing patent citations, publication and patent outputs of multinational corporations (MNCs) in 'thin film' technology. In particular we explore different characteristics of knowledge production and knowledge utilization of these firms. The results indicate no correlation between intensity of research activity and patents produced by the MNCs. The relationship between scientific and technological knowledge generation as well as the linkage between science and technology appear to be firm-specific rather than dependent on a technological or industrial sector. The dispersion of journal sources for the majority of patent citations of scientific literature as well as for the majority of scientific outputs is narrow. Basic journals play an important role in patent citation as well as in addressing research of MNCs in thin-film technology.     

Patent citation analysis: A policy analysis tool

Patent citation analysis is a recent development which uses bibliometric techniques to analyse the wealth of patent citation information. This paper describes the various facets of patent citations and patent citation studies, and their important applications. Construction of technology indicators being an important use of patent citations, various patent citation based technological indicators and their applications are also described.     

Using patent statistics as knowledge base indicators in the biotechnology sectors: An application to France,Germany and the U.K.

In order to formulate firm, national or regional technology policy, it is necessary to have indicators that can measure technological competence. This paper develops a set of indicators using patent statistics to compare the “knowledge base” of individuals, laboratories, firms or nations. These indicators are then applied to the patent applications in France, Germany and the U.K. in the biotechnology sectors. The paper shows that France is lagging behind Germany and the U.K. in technology stocks (or its patent applications) in all biotechnology fields. However it is the leader in the technology network supporting the foods industry. It has a comparative advantage in terms of either technology stock counts or networks in Genetic Engineering, Pharmaceuticals, Foods, Chemicals, Cell Culture and Biocatalysis. Germany is leading in many sectors, but in all sectors in which it is a leader, it is a specialized leader, i.e. its technology networks need to be more extensive. It has a comparative advantage in terms of either technology stock counts or networks in all sectors except Genetic Engineering, Pharmaceuticals, Agriculture and Cell Culture. The U.K. is the leader in the important field of Genetic Engineering and in terms of the entire technology networks in the biotechnology sectors. It has a comparative advantage in terms of either technology stock counts or networks in Genetic Engineering, Pharmaceuticals, Agriculture and Purification. This revised version was published online in August 2006 with corrections to the Cover Date.     

Patents cited in the scientific literature: An exploratory study of 'reverse' citation relations

This paper reports on a new approach to study the linkage between science and technology. Unlike most contributions to this area we do not trace citations of scientific literature in patents but explore citations of patents in scientific literature. Our analysis is based on papers recorded in the 1996-2000 annual volumes of the CD-Edition of Science Citation Index (SCI) of the Institute for Scientific Information (ISI) and patent data provided by the US Patent and Trademark Office. Almost 30,000 US patents were cited by scientific research papers. We analysed the citation links by scientific fields and technological sectors. Chemistry-related subfields tended to cite patents more than other scientific area. Among technological sectors, chemical clearly dominates followed by drugs and medical patents as the most frequently cited categories. Further analyses included a country-ranking based on inventor-addresses of the cited patents, a more detailed inspection of the ten most cited patents, and an analysis of class-field transfers. The paper concludes with the suggestions for future research. One of them is to compare our 'reverse' citation data with 'regular' patent citation data within the same classification system to see whether citations occur, irrespectively of their directionality, in the same fields of science and technology. Another question is as to how one should interpret reverse citation linkages.     

A comparative study of patent counts by the inventor country and the assignee country

This paper compared and contrasted patent counts by examining the inventor country and the assignee country. An empirical analysis of the patent data revealed how assignment principles (i.e. by the inventor country and by the assignee county) and counting methods (i.e. whole counts, first country and fractional counts) generate different results. Quadrant diagrams were utilised to present the patent data of the 33 selected countries. When countries had similar patent counts by inventor country with patent counts by assignee country, all the countries allocated along the diagonal line in the quadrant diagram were developed countries. When countries had more patent counts by inventor than by assignee, developed countries were more likely to sit in the right upper section of the quadrant diagram, while more developing countries were situated in the left lower section. Countries with higher patent counts by assignee than by inventor were more likely to be tax havens. A significant contribution of this paper resides in the recommendation that patent counts be analysed using both the inventor country and the assignee country at the same time if meaningful implications from patent statistics are to be obtained.     

Citations as a measure of technological impact: A review of forward citation-based measures

The number of forward citations a patent receives accumulates over time and appears to be correlated to the patent‘s (i.e. invention's) technological impact. A dominant theory suggests that highly cited patents contain an important technological advance. However, a variety of citation based measures have been proposed by different authors. This study, via a narrative literature review, identified nine forward citation-based measures that appear of particular relevance. We describe each measure and present them in a comparative format.The measures are divided into two broad categories: firstly the ones that are particularly relevant to the patent level (citation index, forward citation frequency, generality, influence), and secondly the ones that are relevant to the patent portfolio level (current impact index, herfindal-hirschman index, hindrance index, relative patent position, technology strength).We hope research scholars and industrial users find this review helpful for citation analysis and intellectual property analytics, especially when wanting to employ forward citation-based measures to assess technological impact.     

A pilot study on the connection between scientific fields and patent classification systems

Methods to link academic research achievements with innovative industries have gained considerable awareness worldwide in recent years. Subsequently, responding to industries’ demand to reinforce the linkage between scientific research and industries is an issue awaiting urgent resolution for the government. Previous scientific pertaining to the linkage between scientific fields and (academic papers) technological fields (technology patents) primarily focus on non-patent research or university–industry collaboration. However, these studies failed to highlight the type of linkages between science and technological fields. Therefore, we conducted a pilot study to identify the core scientific fields in different technological fields. In addition to the proposed network maps linking scientific and technological fields, this study also identified the core scientific fields for patent development, including materials science, multidisciplinary; engineering, chemical; physics, applied; nanoscience and nanotechnology; and chemistry, physical. Due to the scarcity of research pertaining to the linkage of scientific fields and technological fields, the government, research and development units, and universities lack a framework for linking fundamental scientific research with the development of industry technologies. Therefore, in this study, we used an author–inventor network to analyze this research topic, expecting that the results can serve as a reference for further research.     

Prediction of emerging technologies based on analysis of the US patent citation network

The network of patents connected by citations is an evolving graph, which provides a representation of the innovation process. A patent citing another implies that the cited patent reflects a piece of previously existing knowledge that the citing patent builds upon. A methodology presented here (1) identifies actual clusters of patents: i.e., technological branches, and (2) gives predictions about the temporal changes of the structure of the clusters. A predictor, called the citation vector, is defined for characterizing technological development to show how a patent cited by other patents belongs to various industrial fields. The clustering technique adopted is able to detect the new emerging recombinations, and predicts emerging new technology clusters. The predictive ability of our new method is illustrated on the example of USPTO subcategory 11, Agriculture, Food, Textiles. A cluster of patents is determined based on citation data up to 1991, which shows significant overlap of the class 442 formed at the beginning of 1997. These new tools of predictive analytics could support policy decision making processes in science and technology, and help formulate recommendations for action.     

Influences of counting methods on country rankings: a perspective from patent analysis

The counting of patents and citations is commonly used to evaluate technological innovation and its impact. However, in an age of increasing international collaboration, the counting of international collaboration patents has become a methodological issue. This study compared country rankings using four different counting methods (i.e. whole counting, straight counting, whole-normalized counting, complete-normalized counting) in patent, citation and citation-patent ratio (CP ratio) counts. It also observed inflation depending on the method used. The counting was based on the complete 1992–2011 patent and citation data issued by United States Patent and Trademark Office. The results show that counting methods have only minor effects on country rankings in patent count, citation count and CP ratio count. All four counting methods yield reliable country ranks in technology innovation capability and impact. While the influences of counting methods vary between patent count, citation count and CP ratio count, counting methods may exert slightly greater effects on CP ratio counts than on patent and citation counts. As for the inflation, the distributions of higher and lower inflation by the four counting methods are different in patent, citation and CP ratio counts.     

Going much beyond the Durfee square: enhancing the <Emphasis Type="Italic">h</Emphasis><Subscript>T</Subscript> index

The objective of this research is to develop a new patent bibliometric performance measure by using modified citation rate analyses with dynamic backward citation windows. Cited half-life employed in bibliometrics was adopted in order to establish a model of annual patent backward citation windows. Based on the dynamic behavior of backward citation windows, the annual backward patent citation rates for each technology domain can be calculated to measure its bibliometric performance. It was found that the dynamic backward citation window represents more accurately the citation cycle time which is a key factor on technology assessment. Because different technology domain may have disparate attributes, a normalized backward citation rate was developed to measure the corresponding rank for each domain respect to the entire industry. Three technology domains were then chosen for demonstrative case studies which represent semiconductor, LCD, and drug industries.     

Patent and literature statistics – The case of optoelectronics

The aim of this paper is to provide an overview of different statistical analyses from patent and literature databases that in combination are helpful for a variety of mostly strategic decision settings in firms. For the case of optoelectronics we assess the patenting and publishing activity of firms and individuals and their citation frequency.The analyses identified leading players in the field, revealed technological dependencies, and the existence of patent clusters as patenting strategies. Co-citation analysis highlighted technological similarities between two firms involved in patent litigation trials. In this science-based technology field individuals combining characteristics of key inventors (a high activity and citation level in patenting) as well as core scientists (a high activity and citation frequency level in publishing) – therefore labelled “R&D dualists” – successfully bridge the gap between science and technology, but are exceptionally rare. Citation-weighted patent counts demonstrated the pivotal impact of one “R&D dualist” in an industrial R&D laboratory, severely affecting the laboratories’ outcome when this individual left. An increasing level of R&D cooperation in particular technological subfields after the individual’s departure could be found. However, patent analysis did not find evidence for long-term competence transfer in these subfields.     

Exploring the “value” of academic patents: IP management practices in UK universities and their implications for Third-Stream indicators

Third-Stream activities have become increasingly important in the UK. However, valuing them in a meaningful way still poses a challenge to science and technology analysts and policy makers alike. This paper reviews the general literature on “patent value” and assesses the extent to which these established measures, including patent citation, patent family, renewal and litigation data, can be applied to the university context. Our study examines indicators of patent value for short and mid-term evaluation purposes, rather than indicators that suffer from long time lags. We also explore the extent to which differences in IP management practices at universities may have an impact on the validity and robustness of possible indicators. Our observations from four UK universities indicate that there are considerable differences between universities as to how they approach the IP management process, which in turn has implications for valuing patents and how they track activity in this area. In their current form, data as collected by universities are not sufficiently robust to serve as the basis for evaluation or resource allocation.     

Exploring the effect of dual use on the value of military technology patents based on the renewal decision

Concerns regarding the high level of research and development (R&D) expenditure on military technology have prompted many nations to pursue a dual-use regime in military R&D. However, the value of dual-use military technology has not yet been quantitatively investigated. We explore whether military technology with a higher level of duality has been more valuable than that with a lower level of duality. We assume that the patent of valuable military technology was renewed until its termination. We retrieve military patents from the United States Patent and Trademark Office during 1976–2014 based on their International Patent Classification (IPC) as F41 or F42. Then, we propose three indicators to assess the duality level of them. The first indicator is based on the determination of whether the patented technology is utilizable in both the military and the civilian sectors using its IPC. For the second indicator, we estimate the potential of convergence of a patented technology with various technological fields using the degree of centrality of the IPC’s co-occurrence network. The third indicator is based on ratio of forward citation by the civilian sector over the total number of forward citations as a measurement of technology diffusion toward the civilian sector. Using logistic regression, we found that the first two indicators are positively associated with patent renewal decision, while the last indicator is nonsignificant. The effects of the two significant indicators suggests that military technologies are more valuable when the technology itself can be used in various sectors, including the civilian sector, and can be converged with technologies in different fields. However, the nonsignificant influence of the third variable suggests that the relation between patent value and diffusion effects toward following inventions is not confined to the civilian sector. Our findings provide evidence of the impact of dual-use policies in military R&D.     

Patent Citations in a Novel Field of Technology — What Can They Tell about Interactions between Emerging Communities of Science and Technology?

This paper aims to contribute to a better understanding of patent citation analysis in general and its application to novel fields of science and technology in particular. It introduces into the subject-matter by discussing an empirical problem, the relationship of nano-publications and nano-patents as representations of nano-science and nano-technology. Drawing on a variety of sources, different interpretations of patent citations are presented. Then, the nature of patent citations is further investigated by comparing them to citations in the scientific literature. After characterizing the citation linkage as indicators of reciprocal relationships between science and technology, patent citations in nano-science and technology are analyzed in terms of interfield and organizational knowledge-flows.     

The citation impact of social sciences and humanities upon patentable technology

This paper examines the citation impact of papers published in scientific-scholarly journals upon patentable technology, as reflected in examiner- or inventor-given references in granted patents. It analyses data created by SCImago Research Group, linking PATSTAT’s scientific non-patent references (SNPRs) to source documents indexed in Scopus. The frequency of patent citations to journal papers is calculated per discipline, year, institutional sector, journal subject category, and for “top” journals. PATSTAT/Scopus-based statistics are compared to those derived from Web of Science/USPTO linkage. A detailed assessment is presented of the technological impact of research publications in social sciences and humanities (SSH). Several subject fields perform well in terms of the number of citations from patents, especially Library and Information Science, Language and Linguistics, Education, and Law, but many of the most cited journals find themselves in the interface between SSH and biomedical or natural sciences. Analyses of the titles of citing patents and cited papers are presented that shed light upon the cognitive content of patent citations. It is proposed to develop more advanced indicators of citation impact of papers upon patents, and ways to combine citation counts with citation content and context analysis.

     

Identifying rapidly evolving technological trends for R&;D planning using SAO-based semantic patent networks

Patents constitute an up-to-date source of competitive intelligence in technological development; thus, patent analysis has been a vital tool for identifying technological trends. Patent citation analysis is easy to use, but fundamentally has two main limitations: (1) new patents tend to be less cited than old ones and may miss citations to contemporary patents; (2) citation-based analysis cannot be used for patents in databases which do not require citations. Naturally, citation-based analysis tends to underestimate the importance of new patents and may not work in rapidly-evolving industries in which technology life-cycles are shortening and new inventions are increasingly patented world-wide. As a remedy, this paper proposes a patent network based on semantic patent analysis using subject-action-object (SAO) structures. SAO structures represent the explicit relationships among components used in a patent, and are considered to represent key concepts of the patent or the expertise of the inventor. Based on the internal similarities between patents, the patent network provides the up-to-date status of a given technology. Furthermore, this paper suggests new indices to identify the technological importance of patents, the characteristics of patent clusters, and the technological capabilities of competitors. The proposed method is illustrated using patents related to synthesis of carbon nanotubes. We expect that the proposed procedure and analysis will be incorporated into technology planning processes to assist experts such as researchers and R&D policy makers in rapidly-evolving industries.     

Patent citation network analysis of core and emerging technologies in Taiwan: 1997–2008

Identifying core technologies and emerging technologies is essential for formulating national technology strategies and policies for pursuing technological competitive advantage. This study presents a quantitative method for identifying core technologies and emerging technologies in the Taiwan technological innovation system. The objective was to gain an overview of technological development in the country by analyzing patent citation networks and by identifying five core technologies and emerging technologies in Taiwan based on United States Patent and Trademark Office (USPTO) patents granted to Taiwan during 1997–2008. The findings indicate the most appropriate management of technology and innovation and the best patent strategy and technology policy that the Taiwan government should pursue. Research institutes, industries and academia are also given research directions for choosing the technologies in which they should invest resources in order to strengthen the Taiwan technological innovation system and to increase its competitive advantage in global technology.     

Transnational citation, technological diversity and small world in global nanotechnology patenting

Despite the extensive studies conducted in the field of nanotechnology based on US patent data, the choice of a single database may impede a wider view of this technology frontier. Based on patent data from the Derwent Innovation Index database that covers the data of 41 major patent offices, we review the development of nanotechnology patenting from the dimensions of patenting authority and technological classification. We find that a small number of countries dominating the technology have similar technological diversity in terms of nanotechnology patents. After the discussion and summary of the citation modes and citation rate curve, we construct the patent citation networks at the patent document level and discuss the distinctive transnational citation patterns. We then use Search Path Count Method to extract the technological trajectory, where we find very high selectiveness. In the final section of this paper, we discover the small world phenomenon in the citation networks, which is widely investigated in undirected networks such as co-authorship networks, but rarely touched in citation networks due to the limitations of the presumptions. We propose the reachable path length and citation clustering in the revised small world model for acyclic directed networks and provide the realistic meaning of the new measures.