Number of Backward Patent Citations as a Quantitative Indicator of Prior Art (Japanese)

Patent citations have been widely utilized to measure inter-organizational knowledge flows. Measurement of knowledge flow is important in understanding how "open innovation" influences inventive activities through such means as personnel movement, venture capital, technology licensing, and R&D cooperation with universities. However, it is known that patent citations contain noise in measuring knowledge spillover. Moreover, there remains another question -- whether or not inventors' citations evenly reflect inventors' recognition of prior knowledge within and across organizational boundaries. Since some citations come from inventors' own organizations, prior patents within the organization might show up as citations more often than those outside of organizational boundaries. If that is the case, biased measurement of cumulative innovations through citations should be considered when we try to evaluate knowledge diffusion within hierarchies and in the market. With this motivation in mind, this study matches backward citations with the RIETI Inventor Survey. In particular, survey responses concerning the dependence on prior patents and the location of the prior patents (whether or not prior patents come from the same firm) are analyzed in combination with backward citations. First, backward citations are confirmed to be consistent with the survey responses in the sense that the ratio of internal citations over outside citations is positively and significantly correlated with the survey responses, suggesting that prior patents existed internally. However, further analyses using binary choice models show asymmetric results regarding internal and outside citations. Only when there are more citations inside inventors' firm boundaries, does the probability of a positive response to the survey question, "the invention was substantially dependent on prior patents" increase. In contrast, the number of outside citations is not a significant factor. Only the number of internal citations seems correlated with the probability of inventors' perception of the prior patents that they were dependent upon. The results hold not only with the Japan Patent Office (JPO) inventor citations and with U.S. citations overall, but also with JPO examiner citations. Since JPO examiners have little incentive to focus only on prior arts inside the inventors' organization, the "locality" of inventors' (revealed) awareness of prior patents creates a new puzzle. We can at least conclude that, compared with the number of backward self-citations, the number of non-self citations has a different character as a proxy variable for inventors' perceptions. A follow-up inventor survey is planned to scrutinize how citations within firm boundaries differ from those across firm boundaries.

Backward Patent Citations and Inventors' Recognition of Differential Influences (Japanese)

While numerous empirical investigations of cumulative innovation have utilized patent citation as quantitative metric, most of the existing studies assume away differences in the relative importance of citing relationships at the micro-analytic level. In other words, no weight has been given to each citer-cited pair with respect to an individual patent. This paper takes advantage of the RIETI Inventor Survey (supplementary survey, conducted in 2008) in order to identify the determinants of relative importance, as recognized by the inventors, between their technological predecessors. The results reveal that the number of forward examiner citations (not inventor citations) which a cited patent generally receives is positively correlated with the importance recognized by its inventor for the specific invention. In addition, only the maximum number of (not the total of) forward examiner citations that cited patents receive have a consistently positive correlation with the recognition of the existence of preceding patents by its inventor. The findings imply that examiner citations are more useful than inventor citations to estimate relative significance between previous patents. Also, a very skewed distribution of influences from various cited patents appears to be the cause of seemingly uneven impacts from within-the-firm and out-of-the-firm technological sources, which was found in the Inventor Survey conducted in 2007.

Investigation of affecting parameters of Electrophoretic deposition (EPD) method in (Bi0.5Na0.5)TiO3-Hexagonal BaTiO3 and their properties

Nowadays, eco-friendly materials have been attracting attention worldwide since the legislation of RoHS/WEEE directives in Europe. (Bi0.5Na0.5)TiO3-BaTiO3 (BNT-BT) systems are well known candidate of lead-free piezoelectric materials. However, BNT-BT systems have relatively low piezoelectric constant (d33 ~ 140 pC/N) which is difficult to apply in commercial products. In spite of this problem, BNT-BT systems have good potential because it is easy to apply mass production. Electrophoretic deposition method (EPD) has good advantage in mass production because size and shape of green ceramics is easily controlled by control of electrode. Moreover, it is reported that EPD method can be fabricated textured ceramics using high magnetic field and texture technique is important in enhancing piezoelectric properties. Our final goal is making [111] oriented BNT-BT ceramics which have enhanced piezoelectric properties and appreciate for mass production. Please click Additional Files below to see the full abstract

ニホン ノ トッキョ インヨウ ニオケル スイイセイ ノ ケントウ ERGMs(Exponential Random Graph Models) テキヨウ ノ ココロミ

1）経済学・経営学において特許引用はきわめて広範囲に利用されているが、ネットワークと　してみたときのクラスタ性には実証検討が進んでいない。そこで日本特許について、クラスタ　性の一側面である推移性（transitivity）を中心的な関心におき、ERGMを含むネットワーク分　析を試行した。2）　日本の審査官特許引用と発明者特許引用それぞれ全体を方向付きネットワークとしてみた　とき、後者の推移性指標は、前者よりも高い。3）引用ネットワークをマルコフ・グラフとみなし、推移的トリプル数・同一出願人に属する　引用ペア数・同一国際特許分類クラスに属する引用ペア数をそれぞれネットワーク指標とし　て扱って、統計分析ソフトウエアR環境上のergmパッケージによる検証を限定サンプルにお　いて試みたところ、個々の特許引用に3つの指標は正の影響を与えていると観察された

Current status of clinical background of patients with atrial fibrillation in a community-based survey: The Fushimi AF Registry

AbstractBackgroundAtrial fibrillation (AF) increases the risks of stroke and death, and the prevalence of AF is increasing significantly. Until recently, warfarin was the only oral anticoagulant for stroke prevention, but novel anticoagulants are now under development.Methods and resultsThe Fushimi AF Registry is a community-based survey of AF patients. We aimed to enroll all of the AF patients in Fushimi-ku, which is located at the southern end of the city of Kyoto. Fushimi-ku is densely populated with a total population of 283,000, and is assumed to represent a typical urban community in Japan. On the basis of the general prevalence of AF in the Japanese (0.6%), we estimated the total number of AF patients as 1700. A total of 76 institutions, a large proportion of which were private clinics, participated in the study. At present, we have enrolled 3183 patients from March 2011 to June 2012 (approximately 1.12% of total population). The mean age was 74.2±11.0 years, and 59.3% of subjects were male. The mean body weight was 58.5±13.2kg, and the proportions with a body weight of less than 50kg and 60kg were 25.7% and 55.0%, respectively. The type of AF was paroxysmal in 46.0%, persistent in 7.3%, and permanent in 46.7%. Major co-existing diseases were hypertension (60.6%), heart failure (27.9%), diabetes (23.2%), stroke (19.4%), coronary artery disease (15.0%), myocardial infarction (6.4%), dyslipidemia (42.4%), and chronic kidney disease (26.4%). The mean CHADS2 score was 2.09±1.35: 0 in 11.8% of patients, 1 in 27.1%, and 2 in 29.1%. Warfarin was prescribed in only 48.5% of patients, whereas anti-platelet drugs, mainly aspirin, were prescribed for more than 30% of the patients.ConclusionsThe Fushimi AF Registry provides a unique snapshot of current AF management in an urban community in Japan