34 research outputs found

    Quantitative analysis of the stability of Japan's energy system

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    In order to measure Japan's energy system's stability under an uncertain future availability of energy resources, we built a mathematical programming / economic equilibrium model based upon linear programming techniques. Future uncertainty is expressed as random variables with a given probability distribution, and the economic equilibrium point is obtained by iterative convergent computation. Numerical experiments show an optimal energy supply-demand structure with equilibrium prices of primary energy resources at the future target year, then we obtain supply stability and instability probabilities of our energy system. From shadow price analysis of an optimal solution our energy policy is quantitatively evaluated

    A mathematical programming/economic equilibrium model for the quantitative analysis of the stability of Japan's energy system

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    Japan's energy supply-demand system is fully dependent on the import of primary energy resources from foreign countries. So the availability of primary energy, including crude oil and coal, is a very important factor for the stability of our energy system. In order to measure our energy system's stability under an uncertain future availability of energy resources, we built a mathematical programming / economic equilibrium model based upon linear programming techniques. In the model analysis uncertain future availability of primary energy resources is expressed as random variables with a given probability distribution, and the economic equilibrium point is obtained by iterative convergent computation. From our numerical results we know an optimal energy supply-demand structure with equilibrium prices of primary energy resources at the future target year, and obtain supply stability and instability probabilities of our energy system. Furthermore, applicability of decomposition techniques to our energy model analysis and necessary and sufficient conditions for the stability of our energy system are discussed

    Slow relaxation to equipartition in spring-chain systems

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    In this study, one-dimensional systems of masses connected by springs, i.e., spring-chain systems, are investigated numerically. The average kinetic energy of chain-end particles of these systems is larger than that of other particles, which is similar to the behavior observed for systems made of masses connected by rigid links. The energetic motion of the end particles is, however, transient, and the system relaxes to thermal equilibrium after a while, where the average kinetic energy of each particle is the same, that is, equipartition of energy is achieved. This is in contrast to the case of systems made of masses connected by rigid links, where the energetic motion of the end particles is observed in equilibrium. The timescale of relaxation estimated by simulation increases rapidly with increasing spring constant. The timescale is also estimated using the Boltzmann-Jeans theory and is found to be in quite good agreement with that obtained by the simulation

    Public communication by research institutes compared across countries and sciences: building capacity for engagement or competing for visibility?

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    Leading academic institutions, governments, and funders of research across the world have spent the last few decades fretting publicly about the need for scientists and research organisations to engage more widely with the public and be open about their research. While a global literature asserts that public communication has changed from a virtue to a duty for scientists in many countries and disciplines, our knowledge about what research institutions are doing and what factors drive their 'going public' is very limited. Here we present the first cross-national study of N = 2,030 research institutes within universities and large scientific organisations in Brazil, Germany, Italy, Japan, the Netherlands, Portugal, the United Kingdom, and the United States of America. We find that institutes embrace communication with non-peers and do so through a variety of public events and traditional news media-less so through new media channels-and we find variation across countries and sciences, yet these are less evident than we expected. Country and disciplinary cultures contribute to the level of this communication, as do the resources that institutes make available for the effort; institutes with professionalised staff show higher activity online. Future research should examine whether a real change in the organisational culture is happening or whether this activity and resource allocation is merely a means to increase institutional visibility

    Aprepitant plus granisetron and dexamethasone for prevention of chemotherapy-induced nausea and vomiting in patients with gastric cancer treated with S-1 plus cisplatin

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    Background: We aimed to evaluate the efficacy of a new combination antiemetic therapy comprising aprepitant, granisetron, and dexamethasone in gastric cancer patients undergoing chemotherapy with cisplatin and S-1. Methods: Gastric cancer patients scheduled to receive their first course of chemotherapy with cisplatin (60 mg/m2) and S-1 (80 mg/m2) were treated with a new combination antiemetic therapy aprepitant, granisetron, and dexamethasone on day 1; aprepitant and dexamethasone on days 2 and 3; and dexamethasone on day 4. The patients reported vomiting, nausea, use of rescue therapy, and change in the amount of diet intake, and completed the Functional Living Index-Emesis (FLIE) questionnaire. The primary endpoint was complete response (CR; no emesis and use of no rescue antiemetics) during the overall study phase (0-120 h after cisplatin administration). The secondary endpoints included complete protection (CP; CR plus no significant nausea); change in the amount of diet intake; and the impact of chemotherapy-induced nausea and vomiting (CINV) on daily life during the overall, acute (0-24 h), and delayed (24-120 h) phases. Results: Fifty-three patients were included. CR was achieved in 88.7, 98.1, and 88.7 % of patients in the overall, acute, and delayed phases, respectively. The corresponding rates of CP were 67.9, 96.2, and 67.9 %. Approximately half of the patients had some degree of anorexia. FLIE results indicated that 79.5 % of patients reported "minimal or no impact of CINV on daily life". Conclusions: Addition of aprepitant to standard antiemetic therapy was effective in gastric cancer patients undergoing treatment with cisplatin and S-1. © 2013 Springer Japan

    A Mathematical Programming / Economic Equilibrium Model for the Quantitative Analysis of the Stability

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    Japan's energy supply-demand system is fully dependent on the import of primary energy resources from foreign countries. So the availability of primary energy, including crude oil and coal, is a very important factor for the stability of our energy system. In order to measure our energy system's stability under an uncertain future availability of energy resources, we built a mathematical programming / economic equilibrium model based upon linear programming techniques. In the model analysis uncertain future availability of primary energy resources is expressed as random variables with a given probability distribution, and the economic equilibrium point is obtained by iterative convergent computation. From our numerical results we know an optimal energy supply-demand structure with equilibrium prices of primary energy resources at the future target year, and obtain supply stability and instability probabilities of our energy system. Furthermore, applicability of decomposition techniques to our energy model analysis and necessary and sufficient conditions for the stability of our energy system are discussed. During the years following the Arab oil embargo of 1973, there have been many energy policy debates throughout the world, including Japan. Energy policy debates concern various technical, environmental, social, economical, political and even military problems. Energy policy modeling efforts have increased due to not only the necessity of such interdisciplinary research, but also the greater availability of high speed computers. Since Hoffman [1973] proposed energy network systems analyses for supply-demand energy problems, various systems analysis approaches have been developed. (See e.g. Charpentier [1974] and Manne, et al [19793 for energy models. Also see Shapir

    Numerical Analysis of FitzHugh-Nagumo Neurons on Random Networks

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    We investigate a model of randomly copuled neurons. The elements are FitzHgh-Nagumo excitable neurons. The interactions between them are the mixture of excitatory and inhibitory. When all interactions are excitatory, a rest state is globally stable due to the excitability of neurons. Increasing the number of inhibitory connections, we observe the phase transition from the rest state to an oscillatory state. An analytical description for the critical point of the transition is obtained by means of random matrix theories for an infinite number of neurons, and the result is in good agreement with numerical simulation

    Statistical data analyses to elucidate the causes and improve the countermeasures for preventing train accidents in Japan

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    We investigate train accident data in Japan to elucidate the causes and improve the countermeasures for reducing the number of train accidents. We deal with statistical data on train accidents in the last 15 years, including frequency, types such as derailment and crash, causes and consequences. We review the historical trend of train accidents by applying a statistical modeling approach dealing with both serious accident data and total number of accidents. Probability distributions for explaining this train accident data are shown. We show the results of quantitative data analyses on the train accidents, that occurred at the ground-level crossing and the relationship among utility type of railway company, equipment at the crossing and consequences of the accidents. Probabilistic mathematical models are used in the analyses. Finally, we try to evaluate the effectiveness of the countermeasures for preventing train accidents

    Economic, Energy and Co2 Intensity Valuation in Indonesia's Manufacturing Industry

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    Analisis sektor industri manufaktur lebih banyak fokus pada evaluasi aspek ekonomi, seperti output, nilai tambah, dan kesempatan kerja, namun tidak banyak studi yang secara simultan mencoba untuk mengombinasikan aspek konsumsi energi dan emisi gas karbon dioksida (CO2) di dalam analisis. Kami mengaplikasikan teori grafik (graph theory) untuk memilih industri dominan. Namun, tidak ada satupun industri yang mendominasi semua kriteria. Hasil ini menunjukan bahwa pro-pertumbuhan tidaklah harus sama dengan pro-lingkungan hidup, bahkan kedua kriteria tersebut dapat saling bertengtangan satu dengan lainnya. Kami berargumentasi bahwa perbedaan dalam hal karakteristik industri menjadi penting diperhatikan dalam menilai kinerja industri. Akhirnya, dalam konsteks intervensi kebijakan, kami menyarankan pemerintah perlu menyiapakan indikator intensitas dan membangun kerangka kebijakan yang lebih menyeluruh untuk memacu efisiensi energi
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