Search

Presents information on the symposium "New Trends in Computational and Optimization Algorithms (NTOC2001)," organized and sponsored by the Institute of Statistical Mathematics, Tokyo, Japan from December 9 to 13, 2001. Topics of the symposium; Introduction to papers presented at the symposium.

This paper provides details of a successful application where the Column Generation algorithm was used to combine Constraint Programming and Linear Programming. In the past, constraint programming and linear programming were considered to be two competing technologies that solved similar types of problems. Both these technologies had their strengths and weaknesses. This paper shows that the two technologies can be combined together to extract the strengths of both these technologies. Details of a real-world application to optimize bus driver duties is given here. This system was developed by ILOG for a major software house in Japan using ILOG-Solver and ILOG-CPLEX, constraint programming and linear programming C/C++ libraries. [ABSTRACT FROM AUTHOR]

Background: An innovative measurement system using a computerized adaptive testing technique based on the item response theory (CAT) has been expanding to measure mental health status. However, little is known about details in its measurement properties based on the empirical data. Moreover, the response time (RT) data, which are not available by a paper-and-pencil measurement but available by a computerized measurement, would be worth investigating for exploring the response behavior. Purpose: We aimed at constructing the CAT to measure depressive symptomatology in a community population and exploring its measurement properties. Also, we examined the relationships between RTs, individual item responses, and depressive levels. Method: For constructing the CAT system, responses of 2061 workers and university students to 24 depression scale plus four negatively revised positive affect items were subjected to a polytomous IRT analysis. The stopping rule was set for standard error of estimation < 0.30 or the maximum 15 items displayed. The CAT and non-adaptive computer-based test (CBT) were administered to 209 undergraduates, and 168 of them administered again after 1 week. Results: On average, the CAT was converged by 10.4 items. The θ values estimated by CAT and CBT were highly correlated ( r = 0.94 and 0.95 for the 1st and 2nd measurements) and with the traditional scoring procedures ( r's > 0.90). The test-retest reliability was at a satisfactory level ( r = 0.86). RTs to some items significantly correlated with the θ estimates. The mean RT varied by the item contents and wording, i.e., the RT to positive affect items required additional 2 s or longer than the other subscale items. Conclusion: The CAT would be a reliable and practical measurement tool for various purposes including stress check at workplace. [ABSTRACT FROM AUTHOR]

As an increase in gastroesophageal reflux disease (GERD) has been reported in Japan, and public interest in GERD has been increasing, the Japanese Society of Gastroenterology published the Evidence-based Clinical Practice Guidelines for GERD (1st edition) in 2009. Six years have passed since its publication, and there have been a large number of reports in Japan concerning the epidemiology, pathophysiology, treatment, and Barrett's esophagus during this period. By incorporating the contents of these reports, the guidelines were completely revised, and a new edition was published in October 2015. The revised edition consists of eight items: epidemiology, pathophysiology, diagnosis, internal treatment, surgical treatment, esophagitis after surgery of the upper gastrointestinal tract, extraesophageal symptoms, and Barrett's esophagus. This paper summarizes these guidelines, particularly the parts related to the treatment for GERD. In the present revision, aggressive proton pump inhibitor (PPI) maintenance therapy is recommended for severe erosive GERD, and on-demand therapy or continuous maintenance therapy is recommended for mild erosive GERD or PPI-responsive non-erosive GERD. Moreover, PPI-resistant GERD (insufficient symptomatic improvement and/or esophageal mucosal break persisting despite the administration of PPI at a standard dose for 8 weeks) is defined, and a standard-dose PPI twice a day, change in PPI, change in the PPI timing of dosing, addition of a prokinetic drug, addition of rikkunshito (traditional Japanese herbal medicine), and addition of histamine H2-receptor antagonist are recommended for its treatment. If no improvement is observed even after these treatments, pathophysiological evaluation with esophageal impedance-pH monitoring or esophageal manometry at an expert facility for diseases of the esophagus is recommended. [ABSTRACT FROM AUTHOR]

A novel multimodal and bio-inspired approach to biomedical signal processing and classification is presented in the paper. This approach allows for an automatic semantic labeling (interpretation) of sleep apnea events based the proposed data-driven biomedical signal processing and classification. The presented signal processing and classification methods have been already successfully applied to real-time unimodal brainwaves (EEG only) decoding in brain-computer interfaces developed by the author. In the current project the very encouraging results are obtained using multimodal biomedical (brainwaves and peripheral physiological) signals in a unified processing approach allowing for the automatic semantic data description. The results thus support a hypothesis of the data-driven and bio-inspired signal processing approach validity for medical data semantic interpretation based on the sleep apnea events machine-learning-related classification. [ABSTRACT FROM AUTHOR]

We developed a 3D archive system for Japanese traditional performing arts. The system generates sequences of 3D actor models of the performances from multi-view video by using a graph-cuts algorithm and stores them with CG background models and related information. The system can show a scene from any viewpoint as follows; the 3D actor model is integrated with the background model and the integrated model is projected to a viewpoint that the user indicates with a viewpoint controller. A challenge of generating the actor models is how to reconstruct thin or slender parts. Japanese traditional costumes for performances include slender parts such as long sleeves, fans and strings that may be manipulated during the performance. The graph-cuts algorithm is a powerful 3D reconstruction tool but it tends to cut off those parts because it uses an energy-minimization process. Hence, the search for a way to reconstruct such parts is important for us to preserve these arts for future generations. We therefore devised an adaptive erosion method that works on the visual hull and applied it to the graph-cuts algorithm to extract interior nodes in the thin parts and to prevent the thin parts from being cut off. Another tendency of the reconstruction method using the graph-cuts algorithm is over-shrinkage of the reconstructed models. This arises because the energy can also be reduced by cutting inside the true surface. To avoid this tendency, we applied a silhouette-rim constraint defined by the number of the silhouette-rims passing through each node. By applying the adaptive erosion process and the silhouette-rim constraint, we succeeded in constructing a virtual performance with costumes including thin parts. This paper presents the results of the 3D reconstruction using the proposed method and some outputs of the 3D archive system. [ABSTRACT FROM AUTHOR]

The repletion rate of guide dogs for visually handicapped persons is roughly 10% nationwide. The reasons for this low rate are the long training period and the expense for obtaining a guide dog in Japan. Motivated by these two reasons, we are developing guide-dog robots. The major objective is to develop an intelligent human-robot interface. This paper describes two novel interface algorithms and strategy to guide visually handicapped person. We developed new leading edge searching method, which uses a single laser range finder (LRF) developed to find the center of the corridor in an indoor environment. We also developed a new twin cluster trace method that can recognize the led-person's walking conditions measured by the LRF. The algorithm allows the guide-dog robot to accurately estimate and anticipate the led-person's next move. We experimentally verified these algorithms. The results show that the algorithms are reliable enough to enable the guide-dog robot and the led-person to maneuver in a complex corridor environment. [ABSTRACT FROM AUTHOR]

In this paper, we describe an intelligent location-aware city guide system, which adapts to each user’s preferences, and uses an intuitive “metal detector” interface for navigation. Our system analyzes each user’s past location data history to estimate individual preferences, and allows users to find shops that match their tastes in the same way a metal detector would be used to detect metal objects. The procedure with which the system picks out shops that match each user’s preferences includes a newly developed place learning algorithm, which can efficiently find frequented places, complete with their proper names (e.g. “The Ueno Royal Museum”). We have conducted a series of evaluation tests at a popular shopping district inside Tokyo, and the results validate the effectiveness of our overall approach. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the prevalence of hoarseness and its association with the severity of dysphagia in patients with sarcopenic dysphagia. Design: Cross-sectional study using the Japanese sarcopenic dysphagia database. Setting: 19 hospitals including 9 acute care hospitals, 8 rehabilitation hospitals, 2 long-term care hospitals, and 1 home visit rehabilitation team. Participants: 287 patients with sarcopenic dysphagia, aged 20 years and older. Measurements: Sarcopenic dysphagia was diagnosed using a reliable and validated diagnostic algorithm for the condition. The presence and characteristics of hoarseness classified as breathy, rough, asthenic, and strained were assessed. The prevalence of hoarseness and the relationship between hoarseness and Food Intake LEVEL Scale (FILS) were examined. Order logistic regression analysis adjusted for age, sex, naso-gastric tube, and handgrip strength was used to examine the relationship between hoarseness and FILS at baseline and at follow-up. Results: The mean age was 83 ± 10 years. Seventy-four (26%) patients had hoarseness, while 32 (11%), 20 (7%), 22 (8%), and 0 (0%) patients had breathy, rough, asthenic, and strained hoarseness, respectively. Median FILS at the initial evaluation was 7 (interquartile range, 5–8). Hoarseness (β=0.747, 95% confidence intervals= 0.229, 1.265, p=0.005), age, sex, naso-gastric tube, and handgrip strength were associated independently with baseline FILS, while hoarseness (β=0.213, 95% confidence intervals= −0.324, 0.750, p=0.438) was not associated independently with the FILS at follow-up. Conclusions: Hoarseness was associated with the severity of dysphagia at baseline, however not a prognostic factor for sarcopenic dysphagia. Resistance training of swallowing and respiratory muscles and voice training as part of rehabilitation nutrition might be useful for treating sarcopenic dysphagia. [ABSTRACT FROM AUTHOR]

Privacy preserving data mining for medical information is an important issue to guarantee confidentiality of integrated multiple data sets. In this paper, we propose a secured scheme to estimate related risk of cancers accurately and effectively in a privacy-preserving way. We study models to configure the appropriate set of attributes to reduce risk of identity of an individual from being determined. We examine the proposed privacy preserving protocol for encrypted hypothesis test, using actual cohort data supplied by National Cancer Center. [ABSTRACT FROM AUTHOR]

Summary: Areal BMD (aBMD) from DXA is not a sufficiently accurate predictor of fracture. Novel volumetric BMD derived from 3D modeling of the hip from DXA images significantly improved the predictive ability for hip fracture relative to aBMD at the femoral neck, but not aBMD at the total hip. Introduction: To clarify whether volumetric and geometric indices derived from novel three-dimensional (3D) modeling of the hip using dual-energy X-ray absorptiometric (DXA) images improve hip fracture prediction relative to areal bone mineral density (aBMD). Methods: We examined 1331 women who had completed the baseline survey and at least one follow-up survey over 20 years (age 40–79 years at baseline). Each survey included aBMD measurement at the hip by DXA. Volumetric and geometric indices of the hip at baseline and the 10-year follow-up were estimated from DXA images using a 3D modeling algorithm. Incident hip fractures during the 20-year follow-up period were identified through self-report. Cox proportional hazards regression models allowing for repeated measurements of predictors and outcomes were constructed, and their predictive ability for hip fracture was evaluated using areas under receiver operating characteristic curves (AUCs) and net reclassification improvement (NRI) over aBMD at the femoral neck (FN) and total hip (TH) as references. Results: During a median follow-up of 19.8 years, 68 incident hip fractures were identified (2.22/1000 person-years). A significantly larger AUC of trabecular volumetric BMD (vBMD) at the total hip (AUC = 0.741), femoral neck (AUC = 0.748), and intertrochanter (AUC = 0.738) and significant NRI (0.177, 0.149, and 0.195, respectively) were observed compared with FN-aBMD (AUC = 0.701), but not TH-aBMD. Conclusions: vBMD obtained from 3D modeling using routinely obtained hip DXA images significantly improved hip fracture risk prediction over conventional FN-aBMD, but not TH-aBMD. Trial registration: The Japanese Population-Based Osteoporosis (JPOS) Cohort Study was retrospectively registered as UMIN000032869 in the UMIN Clinical Trials Registry on July 1, 2018. [ABSTRACT FROM AUTHOR]

Purpose: Adverse events (AEs) caused by polypharmacy have recently become a clinical problem, and it is important to monitor the safety profile of drug-drug interactions (DDIs). Mining signals using the spontaneous reporting systems is a very effective method for single drug-induced AE monitoring as well as early detection of DDIs. The objective of this study was to compare signal detection algorithms for DDIs based on frequency statistical models. Methods: Five frequency statistical models: the Ω shrinkage measure, additive (risk difference), multiplicative (risk ratio), combination risk ratio, and chi-square statistics models were compared using the Japanese Adverse Drug Event Report (JADER) database as the spontaneous reporting system in Japan. The drugs targeted for the survey are all registered and classified as "suspect drugs" in JADER, and the AEs targeted for this study were the same as those in a previous study on Stevens-Johnson syndrome (SJS). Results: Of 3924 pairs that reported SJS, the number of signals detected by the Ω shrinkage measure, additive, multiplicative, combination risk ratio, and chi-square statistics models was 712, 3298, 2252, 739, and 1289 pairs, respectively. Among the five models, the Ω shrinkage measure model showed the most conservative signal detection tendency. Conclusion: Specifically, caution should be exercised when the number of reports is low because results differ depending on the statistical models. This study will contribute to the selection of appropriate statistical models to detect signals of potential DDIs. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Atmospheric Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: Large inter-individual differences in warfarin maintenance dose are mostly due to the effect of genetic polymorphisms in multiple genes, including vitamin K epoxide reductase complex 1 (VKORC1), cytochromes P450 2C9 (CYP2C9), and cytochrome P450 4F2 (CYP4F2). Thus, several algorithms for predicting the warfarin dose based on pharmacogenomics data with clinical characteristics have been proposed. Although these algorithms consider these genetic polymorphisms, the formulas have different coefficient values that are critical in this context. In this study, we assessed the mutual validity among these algorithms by specifically considering racial differences. Methods: Clinical data including actual warfarin dose (AWD) of 125 Japanese patients from our previous study (Eur J Clin Pharmacol 65(11):1097–1103, 2009) were used as registered data that provided patient characteristics, including age, sex, height, weight, and concomitant medications, as well as the genotypes of CYP2C9 and VKORC1. Genotyping for CYP4F2*3 was performed by the PCR method. Five algorithms that included these factors were selected from peer-reviewed articles. The selection covered four populations, Japanese, Chinese, Caucasian, and African-American, and the International Warfarin Pharmacogenetics Consortium (IWPC). Results: For each algorithm, we calculated individual warfarin doses for 125 subjects and statistically evaluated its performance. The algorithm from the IWPC had the statistically highest correlation with the AWD. Importantly, the calculated warfarin dose (CWD) using the algorithm from African-Americans was less correlated with the AWD as compared to those using the other algorithms. The integration of CYP4F2 data into the algorithm did not improve the prediction accuracy. Conclusion: The racial difference is a critical factor for warfarin dose predictions based on pharmacogenomics. [ABSTRACT FROM AUTHOR]

The article focuses on a study which examines large-scale observational evidence of cross-cultural differences in facial behavior using advanced in computer science. Topics discussed include the automated facial coding used, the reliability of the facial action unit detection algorithms across different testing subsets, multilevel regression estimates predicting each facial action's base rate percentage.

We investigated the feasibility of the ensemble Kalman filter (EnKF) to reproduce oceanic conditions south of Japan. We have adopted the local ensemble transformation Kalman filter algorithm based on 20 members' ensemble simulations of the parallelized Princeton Ocean Model (the Stony Brook Parallel Ocean Model) with horizontal resolution of 1/36°. By assimilating satellite sea surface height anomaly, satellite sea surface temperature, and in situ temperature and salinity profiles, we reproduced the Kuroshio variation south of Japan for the period from 8 to 28 February 2010. EnKF successfully reproduced the Kuroshio path positions and the water mass property of the Kuroshio waters as observed. It also detected the variation of the steep thermohaline front in the Kii Channel due to the intrusion of the Kuroshio water based on the observation, suggesting efficiency of EnKF for detection of open and coastal seas interactions with highly complicated spatiotemporal variability. [ABSTRACT FROM AUTHOR]

In the course of the ongoing since 1992 Global Test of the intermediate-term middle-range earthquake forecast/predictions by the algorithms M8 and MSc place and time of each of the mega-earthquakes of 27 February 2010 in Chile and 11 March 2011 in Japan were recognized as in state of increased probability of such events in advance their occurrences. In conjunction with a retrospective analysis of seismic activity preceding the first of a series of mega earthquakes of the 21st century, i.e., 26 December 2004 in the Indian Ocean, these evidences give grounds for assuming that the algorithms of proven validated effectiveness in magnitude ranges M7.5+ and M8.0+ can be applied to predict the mega-earthquakes as well. [ABSTRACT FROM AUTHOR]

The Reverse Tracing of Precursors (RTP) algorithm for the prediction of strong earthquakes has become known owing to the successful predictions of the Tokachi-oki earthquake near Hokkaido Island and the San Simeon earthquake of California in 2003, as well as to other well-documented predictions found on the Internet, some of which also proved to be successful. The RTP predictions with the use of the Japan Meteorological Agency (JMA) data for the zone from Honshu Island to the Middle Kurile Islands deserve special attention. None of the five predictions starting in the middle of 2003, including the last one formulated for the region where the catastrophic earthquake of March 11, 2011, with a magnitude of M = 9 occurred, was a false alarm. One distinctive feature of predictions for this region is the enormous size (about 1000 km) of alarm regions. At the same time, the relatively short alarm interval makes it possible to record a real number of earthquakes with a magnitude of 7.2 and higher during alarm periods, which is about five times larger than on average over the equivalent period, i.e., to reach a probability gain of about five. [ABSTRACT FROM AUTHOR]

Panic disorder (PD) is an anxiety disorder characterized by panic attacks and anticipatory anxiety. Although a number of association studies have been conducted, no gene has been identified as a susceptibility locus. In this study, we conducted a genome-wide association study of PD in 200 Japanese patients and the same number of controls, using the GeneChip Human Mapping 500 K Array Set. Genotypes were determined using the Bayesian Robust Linear Model with Mahalanobis (BRLMM) genotype calling algorithm. The genotype data were data-cleaned using criteria for SNP call rate (95%), Hardy–Weinberg equilibrium (P0.1%) and minor allele frequency (5%). The significance level of the allele P-value was set at 1.0 × 10−6, to make false discovery rate (FDR) <0.05. As a result, seven SNPs were significantly associated with PD, which were located in or adjacent to genes including PKP1, PLEKHG1, TMEM16B, CALCOCO1, SDK2 and CLU (or APO-J). Studies with other samples are required to confirm the results.Journal of Human Genetics (2009) 54, 122–126; doi:10.1038/jhg.2008.17; published online 23 January 2009 [ABSTRACT FROM AUTHOR]

Electronic Health Records (EHRs) are at the heart of reforms aimed at improving the efficiency and quality of healthcare services provided to citizens. Although there is still some skepticism, open source (OS) EHR is a growing phenomenon in health informatics. Given the widespread adoption of OS software (OSS) in several domains, including operating systems, and enterprise systems, the repeated shortfalls faced by healthcare organizations with dominant proprietary EHRs create an opportunity for other alternatives, such as OSS to demonstrate their abilities in addressing these well-documented problems, including inflexibility, high costs, and low interoperability. However, scholars have expressed extensive concerns about the sustainability of OS EHR. Recognizing that OSS project sustainability relies on their governance arrangements, this case study reports on the evolution of the governance and sustainability of a Japanese OS EHR project and provides rich insights to other open source EHR initiative stakeholders, including physicians, developers, researchers, and policy-makers. [ABSTRACT FROM AUTHOR]

We reconstructed the spatiotemporal evolution of seismicity associated with the 2018 Mw 5.6 northern Osaka earthquake, Japan, to discuss the source fault model of the mainshock rupture, the possible link between this rupture and known active faults, and subsequent crustal deformation. We first relocated the hypocenters listed in the earthquake catalog determined by the Japan Meteorological Agency using a double-difference relocation algorithm. We then searched for the earthquake waveforms that closely resembled those of the relocated hypocenters by applying a matched filtering technique to the continuous waveform data. The relocated hypocenters revealed two distinct planar alignments with different fault geometries. A combination of the relocated hypocenters and focal mechanisms suggests that the mainshock rupture initiated on a NNW-SSE-striking thrust fault, dipping ~ 45° to the east, with the rupture propagating to an adjacent sub-vertical ENE-WSW-striking strike-slip fault ~ 0.3 s after the initial mainshock rupture, resulting in the simultaneous propagation of dynamic rupture along the two faults. The strike-slip fault is oblique to the strike of the Arima-Takatsuki Fault, indicating that blind strike-slip faulting occurred. While the east-dipping thrust fault is located deeper than the modeled extent of the Uemachi Fault, a simple extrapolation of the near-surface geometry of the Uemachi fault partially overlaps the mainshock rupture area. Although it is unclear as to whether a blind thrust fault or a deep portion of the Uemachi Fault ruptured during this mainshock-aftershock sequence, a mainshock rupture would have transferred a static stress change of > 0.1 MPa to a portion of the east-dipping thrust fault system. Intensive aftershocks have persisted along the northern and southern edges of the source area, including moderate-magnitude events, whereas the seismicity in the central part of the source area has shown a rapid decay over time. Delayed triggered aftershocks were clearly identified along the northern extension of the rupture area. Because the background seismicity is predominant in this northern area, we interpret that aseismic deformation, such as cataclastic flow lubricated by crustal fluids, triggered this off-fault seismicity. [ABSTRACT FROM AUTHOR]