Jointly Stable Matchings

In the stable marriage problem, we are given a set of men, a set of women, and each person\u27s preference list. Our task is to find a stable matching, that is, a matching admitting no unmatched (man, woman)-pair each of which improves the situation by being matched together. It is known that any instance admits at least one stable matching. In this paper, we consider a natural extension where k (>= 2) sets of preference lists L_i (1 <= i <= k) over the same set of people are given, and the aim is to find a jointly stable matching, a matching that is stable with respect to all L_i. We show that the decision problem is NP-complete already for k=2, even if each person\u27s preference list is of length at most four, while it is solvable in linear time for any k if each man\u27s preference list is of length at most two (women\u27s lists can be of unbounded length). We also show that if each woman\u27s preference lists are same in all L_i, then the problem can be solved in linear time

Fabrication of Anisotropic Polypyrrole Actuators

The novel features of electrochemical actuators fabricated from a cylindrical polypyrrole (PPy) pipe prepared by the electrochemical polymerization techniques have been described. This cylindrical PPy pipe was cut into a rectangular film and its electrochemical and electrical properties were measured. When the inner surface of the PPy film (surface in contact with electrolyte when PPy was polymerized) was insulated and redox was carried out, the PPy film bent toward the outer surface (surface in contact with a slender Teflon pipe when PPy was polymerized) upon reduction and returned to its original shape upon oxidation. However, the bending was not completely accompanished by redox when the outer wall side of the PPy film was insulated. Although such an anomalous bending in the PPy film actuator cannot be explained satisfactorily at this stage, we speculate that the bending phenomena are due to steric effects from cation insertion and extraction

An all ambient, room-temperature processed solar cell from a bare silicon wafer

大気中かつ室温での太陽電池の作製を実現 --低コストで簡便に太陽電池の製造が可能に--. 京都大学プレスリリース. 2023-03-15.Solar cells charging forward: Realizing the potential of creating silicon-based photovoltaics at room temperature. 京都大学プレスリリース. 2023-04-11.Solar cells are a promising optoelectronic device for the simultaneous solution of energy-resource and environmental problems. However, their high cost and slow, laborious production process so far severely hinder a sufficient widespread of clean, renewable photovoltaic energy as a major alternative electricity generator. This undesirable situation is mainly attributed to the fact that photovoltaic devices have been manufactured through a series of vacuum and high-temperature processes. Here we realize a PEDOT:PSS/Si heterojunction solar cell fabricated only in ambient and room-temperature conditions from a plain Si wafer, with an over-10% energy conversion efficiency. Our production scheme is based on our finding that PEDOT:PSS photovoltaic layers actively operate even on highly doped Si substrates, which substantially mitigates the condition requirements for electrode implementation. Our approach may pave the way for facile, low-cost, high-throughput solar cell fabrication, useful in various fields even including developing countries and educational sites

Development of a system for the assessment of a dual-task performance based on a motion-capture device

The authors produced a dual task (DT) that provided a dynamic balance task and a cognitive task in a game system using motion sensors and virtual images. There had been no DT where a cognitive task needs a dynamic balance task that requires full-body motions. We developed and evaluated a game system to assess the performance of the DT. The DT was to solve a Sudoku puzzle using full-body motions like Tái Chi. An ability to perform a DT is intimately related to risk of falls. To evaluate the developed system, we compared the performance of elderly people and young people. Generally, elderly people are at a higher risk of falls. Twenty elderly community-dwelling adults (mean age, 73.0±6.2 years) and 16 young adults (mean age, 21.8±1.0 years) participated in this study. To compare the two groups, we applied an independent-samples t-test. The time taken for the elderly people was 60.6±43.2 s, whereas the time taken for the young people was 16.0±4.8 s. The difference is statistically significant (p<0.05). This result suggests that the developed game system is useful for the evaluation of the DT performance

Local Effects on Strain Seismogram at Matsushiro Seismological Observatory - 1. Love Waves

We proposed a simple method to evaluate local effects on a strain seismogram, and applied the method to investigation of the effects at Matsushiro Seismological Observatory, Japan Meteorological Agency, central Japan, for a Love wave in a period range of 170 - 400 sec. First, we took a ratio of EW to NS component strain for a Love wave on a timefrequency plane. Although NS and EW component strain for a Love wave travelling in any direction have the same amplitude theoretically, the ratio of observed EW to NS component strain was 0.7. Next, we compared the strain seismogram with a velocity seismogram recorded with STS-1 broadband seismometer. A ratio of a partial derivative of a displacement field with respect to time to that with respect to wave propagation direction equals a phase velocity of the wave theoretically. Utilizing the fact, we estimated the phase velocity of a Love wave using the observed velocity and strain seismogram, after NS component strain had been multiplied by 0.7. The result was 24% smaller than the theoretical phase velocity. Finally, we compared the velocity seismogram with other velocity seismograms recorded by STS-1 seismometers at F-net observation stations near Matsushiro and by STS-2 seismometer at Matsushiro, and found that the every deviation from Matsushiro was less than 10%. From these results, we conclude that the EW and NS component strain seismograms have been amplified by factors of 1.32 and 1.88 for a Love wave, respectively. This fact, which may be because of local geology and/or topography effects, must be taken into account when the strain seismogram is used for seismological applications such as the CMT inversion and research on earth¡¦s free oscillations

A study on the correlation between the results of entrance examination and the academic record of the students in the department of laboratory technology

1987年4月から1995年4月の9年間に衛生技術学科へ入学した361名を対象に,高校評点,入学試験(学力試験)成績と,入学後の学業成績,退学,留年,臨床検査技師国家試験との関係を調べた｡ 1)入学者総数は361名で,このうち留年者が39名(10,8%),退学者が18名(5%)であった｡退学者の中には,実質入学辞退者が6名,4年制大学へ進路を変更した者が4名いたが,こうした退学者は1992年度までの入学者に多かった｡ 2)入学者全体では,予定卒業者,留年者,退学者の間で高校評点,入学試験成績には差がなかったが,入学年度ごとにみると,1987,1988年度は留年者が予定卒業者に比べて入学試験の総得点が高い傾向があり,逆に1991年,1993年度は予定卒業者に比べて有意に低かった｡ 3)高校評点は,データが入手できた1991年度以降一貫して留年者の評点が予定卒業者より低く, とくに1991年,1993年度は留年者の評点が有意に低かった｡ 4)留年者も含めて,一般教育科目の成績と専門科目の成績との間に有意を正の相関がみられた｡ 5)高校評点と入学試験成績との間には軽度の相関しかみられなかったが,高校評点および入学試験総合点は入学後の一般教育科目,専門科目の成績と高い正の相関を示した｡ 6)しかし,個々の入学試験科目の得点は,入学後の成績と相関しないか,軽度の相関しかみられなかった｡ 7)国家試験不合格者は,高校評点,入学試験総合点,一般科目平均点,専門科目平均点のいずれも合格者に比べて得点が低かったが,有意差はなかった｡以上の結果から,短期大学部開設当初は留年者,退学者の中に予定卒業者より学力のある学生がいたが,年を追うごとに入学者の学力が均質化し,学力が不十分なために留年する学生が多くなってきていると言える。一般教育科目の成績と専門科目の成績が強い正の相関を示すことは,1年次の成績がそのまま2,3年次の成績に反映されることを示しており,入学当初の動機付けと勉学意欲の喚起が重要なことを示している｡高校評点や学力試験の成績は入学後の成績とよく相関しており,学生選抜の有効な指標であると考えられたが,各入試科目との相関は乏しかったことから,個々の試験科目の問題内容については改善すべき課題があると思われた｡The correlation between the school record in high school, result of entrance examination and the academic record, failure in promotion and withdrawal from school was examined in 361 students entered into department of laboratory technology from 1987 to 1995. 1) Thirty-nine students (10.8%) had failed in promotion, and 18 students (5%) had leaved from the school. The reason of withdrawal was refusal in 6 cases, and 4 students had changed their course to other universities. These cases were more frequent in the period until 1990 than in the period after 1991. 2) There were no differences in the school record in high school and the result of entrance examination among students who graduated scheduled period of attendance (regular students), those who failed in promotion, and those who had leaved the school. However, the students who failed in promotion had got higher score in entrance examination than regular students in 1987 and 1988. In contrast, regular students had got higher score in entrance examination than the students failed in promotion in 1991 and 1993. 3) The school record in high school could be cheked during the period from 1991 to1995. In this period, the students failed in promotion had got lower score in high school than regular students. Especially, the difference was significant in 1991 and 1993. 4) There was a significant positive correlation between the results in examination of general subjects and those in examination of technical and proffesional education. 5) The school records in high school had relatively weak positive correlation with the results of entrance examination. In contrast, both the school record in high school and result of entrance examination had clear positve correlations with both the results in examination of general subjects and technical and proffesional education. 6) However, the result of each subject of entrance examination, i.e. Japanese, Mathematics, English, and Science, had no or weak positive correlation with both the results in examination of general subjects and technical and proffesional education. 7) The students who had not passed the national examination of laboratory technologist had lower score in school record in high school, entrance examination, examination of general subjects and technical and proffesional education, but the diffenreces were not statistically significant. The results of the study indicate that there were students who failed in promotion or leaved school despite their excellent ability during four years following the establishment of School of Health Sciences, but thereafter the ability of students gradually became homogeneous and increased the students who failed in promotion because of insufficient ability. The highly positive correlation between the results in examination of general subjects and those in examination of technical and proffesional education indicate that the results of examination in the first year were directly reflected in the results of examination in second and third year, and that it is important to encourage the students's motivation and volition to study with ardor immediately after the entrance. The positive correlation of school record in high school and result of entrance examination with academic record after the entrance implicate the potential usefulness of school record in high school and result of entrance examination in determining the eligibility to enter the school. However, it is desirable to improve the subjects and problems of entrance examination because the result of each subject of entrance examination was poorly reflected in the academic record

The reliability and validity of the Japanese version of the Daily Record of Severity of Problems (J-DRSP) and Development of a Short-Form version (J-DRSP (SF)) to assess symptoms of premenstrual syndrome among Japanese women

PURPOSE: To assess the validity and reliability of the Japanese version of the Daily Record of Severity of Problems (J-DRSP, 24 items) for evaluating symptoms of premenstrual syndrome (PMS), and to develop a short form version of the J-DRSP. METHODS: Using the "DRSP-JAPAN" smartphone app, we collected daily J-DRSP records from cycle day - 6 (CD - 6) to CD 10, with CD 1 representing the menstruation onset date. Factorial validity (exploratory factor analysis: EFA, confirmatory factor analysis: CFA) and criterion validity were examined, and test-retest reliability (intraclass correlation: ICC) evaluated. The short-form version of the J-DRSP was developed using classical test theory. RESULTS: In total, 304 women participated and 243 recorded symptoms on at least 4 days spanning the week of the luteal phase (CD - 6 to CD 0) and 4 days spanning the week of the follicular phase (CD 4 to CD 10), with CD 0 set as the day before menstruation started. The EFA revealed a two-factor structure. Kaiser-Meyer-Olkin was 0.992, and Bartlett's test of sphericity chi-square was 3653.89 (P < 0.001). However, the model fitness of CFA was found to be suboptimal (comparative fit index (CFI): 0.83, root mean square error of approximation (RMSEA): 0.12). Total scores for J-DRSP and the sum scores for each subscale were higher on CD 0 than on CD 10 (p < 0.001), suggesting validity for some criteria. ICC values for the total J-DRSP score from CD 0 to CD - 1, and between CD 9 to CD 10, were 0.60 (95% CI: 0.48-0.72) and 0.76 (95% CI: 0.69-0.82), respectively. Having eliminated some original items after considering factor loading for each item, we developed an 8-item Short-Form J-DRSP (J-DRSP (SF)) comprising 2 factors (S-Psychological and S-Physical, 4 items for each). CFA showed a better model fit (CFI: 0.99, RMSEA: 0.048), and ICC values in the luteal and follicular phases were 0.61 (95%CI: 0.51-0.68) and 0.70 (95%CI: 0.62-0.77), respectively. CONCLUSION: The J-DRSP has moderate to good reliability and a certain level of validity. The 8-item J-DRSP (SF) has a two-factor structure and can be used effectively among Japanese women to assess their PMS symptoms

Design Elements of Pervasive Games for Elderly Players: A Social Interaction Study Case

We present the design process and evaluation of a pervasive, location-based mobile game created to act as an experiment system and allow evaluation of how different design elements can influence player behaviour, using social interaction as a study case. A feasibility study with a group of community dwelling elderly volunteers from the city of Kyoto, Japan, was performed to evaluate the system. Results showed that the choice of theme and overall design of game was adequate, and that elderly people could understand the game rules and their goals while playing. Points of improvement included reducing the complexity of game controls and changing social interaction mechanics to account for situations when there are only a few players active or players are too far apart

Daily intake of β-cryptoxanthin prevents bone loss by preferential disturbance of osteoclastic activation in ovariectomized mice

AbstractAlthough β-cryptoxanthin, a xanthophyll carotenoid, has been shown to exert an anabolic effect on bone calcification, little attention has been paid thus far to the precise mechanism of bone remodeling. Daily oral administration of β-cryptoxanthin significantly inhibited osteoclastic activation as well as reduction of bone volume in ovariectomized mice. In vitro studies revealed that β-cryptoxanthin inhibited differentiation and maturation of osteoclasts by repression of the nuclear factor-κB-dependent transcriptional pathway. Our results suggest that supplementation with β-cryptoxanthin would be beneficial for prophylaxis and for therapy of metabolic bone diseases associated with abnormal osteoclast activation