自動車産業の2段階サプライチェーンにおけるブルウィップ効果の定量化に関する基礎的解析

自動車産業のサプライチェーンにおけるブルウィップ効果（Bullwhip　Effect）の定量化を行う。サプライチェーンの下位に行くほど需要量のばらつきが増大する現象を「ブルウィップ効果（Bullwhip Effect）」といい，変動に対応するために下位のサプライヤーほど在庫を多く保有する傾向にあり，経営課題が多い。本論文は，完成車メーカーと1次サプライヤー間の2段階サプライチェーンを対象に，内示生産システムにおける不確実性を有する需要をもとにした発注行動からブルウィップ効果の発生要因把握とブルウィップ効果の定量化を行おうとするものである。まず，小売業を主体として進められてきた先行研究について説明し，その導出の前提について考察する。次に，自動車産業の特徴である内示生産システムについて詳述し，内示情報が発注元から提示されるブレを含む参考値であることを示す。また，内示生産システムを基本としたときの発注業務の仕方を述べる。そして，週次内示を使った場合と月次内示を使った場合のそれぞれについてブルウィップ効果の定量化を行い，評価式を提案する。最後に，データ解析から内示情報のブレの特性を分析し，一定の条件下でブルウィップ効果を評価する。ブルウィップ効果の低減方法にも触れる。ブルウィップ効果によりサプライチェーンの非効率性をもたらす。すなわち，過剰な在庫保有，顧客サービスの低下，収益減少，誤った設備投資，不効率な輸送，不適正な生産計画等を引き起こす。ブルウィップ効果の減少は経営効果の向上につながるものである

San Diego, CA 92152--5001

This report summarizes the work conducted to demonstrate and validate the use of the Benthic Flux Sampling Device (BFSD) for quantifying in situ metal contaminant mobility in marine sediments. A complete description of the equipment, processes, and methods is given. Test and demonstration results along with analysis and interpretation are included in the report. Performance and cost analysis is also included. The specific objectives of the project were as follows: 1. Evaluate the quality of water samples collected using the BFSD, specifically for use in determining if a statistically significant flux was occurring at the test locations in comparison to the blank flux results for the BFSD. 2. Evaluate the BFSD for repeatability. 3. Evaluate the logistical and economic resources necessary to operate the BFSD. 4. Evaluate the range of conditions in which the BFSD can be operated. The California Environmental Protection Agency's Technology Certification Program was selected for independent evaluation of the performance objectives. A set of detailed performance claims that embodied the above project objectives were established. A replicate series of three full system blank equipment tests were conducted to statistically establish system baseline performance. Two formal demonstrations were then conducted with evaluator oversight. The demonstrations used contaminated sites in San Diego Bay, CA, and in Pearl Harbor, HI, where fundamental differences allowed the evaluators a broad set of results to compare with claimed performance. Standardized processes and methods were followed. Pre- and post-deployment preparations, logistics, material, and labor costs were also evaluated. The project met its objectives. The two demonstrations were successful and provided evaluators adequate ..

and Environmental Risks (CEIGRAM)

IISD contributes to sustainable development by advancing policy recommendations on international trade and investment, economic policy, climate change and energy, measurement and assessment, and natural resources management, and the enabling role of communication technologies in these areas. We report on international negotiations and disseminate knowledge gained through collaborative projects, resulting in more rigorous research, capacity building in developing countries, better networks spanning the North and the South, and better global connections between researchers, practitioners, citizens and policy-makers. IISD’s vision is better living for all—sustainably; its mission is to champion innovation, enabling societies to liv

Editor's Summary

Manipulation of consciousness is an everyday medical trick−−think anesthesia−−but physicians have only the crudest of tools to detect when a person is not aware. The usual question or physical stimulus does not always provide reliable reactions, and a more precise index is needed to avoid, for example, the conclusion that people who have locked-in syndrome (in which they are aware but cannot respond) are unconscious. Here, Casali et al. have extended their previous work on electrical correlates of consciousness to define an electroencephalographic-derived index of human consciousness [the perturbational complexity index (PCI)] that reflects the information content of the brain's response to a magnetic stimulus. The PCI could allow tracking of consciousness in individual patients. The authors used data already collected from previous experiments, in which they had stimulated people's brains with transcranial magnetic stimulation. By calculating the likely brain regional sources of the signals and then comparing the unique information in each, the authors derived PCI values. The values ranged from 0.44 to 0.67 in 32 awake healthy people, but fell to 0.18 to 0.28 during nonrapid eye movement (NREM) sleep. Then, to see whether a completely different way of inducing unconsciousness had the same effect on PCI, the authors assessed data from patients given various amounts of the anesthetics midazolam, xenon, and propofol. These agents too caused low ''unconscious' ' values for the PCI: midazolam deep sedation, 0.23 to 0.31; propofol, 0.13 to 0.30; and xenon, 0.12 to 0.31

Landscape Ecology vol. 3 nos. 217-227 (1989) SPB Academic Publishing bv, The Hague

A simple model of animal movement on random and patterned landscapes was used to explore the problems of extrapolating information across a range of spatial scales. Simulation results indicate that simple relationships between pattern and process will produce a variety of scale-dependent effects. These theoretical studies can be used to design experiments for determining the nature of scale-dependent processes and to estimate parameters for extrapolating information across scales

Quantifying content consistency improvements through opportunistic contacts

Contacts between mobile users provide opportunities for data updates that supplement infrastructure-based mechanisms. While the benefits of such opportunistic sharing are intuitive, quantifying the capacity increase they give rise to is challenging because both contact rates and contact graphs depend on the structure of the social networks users belong to. Furthermore, social connectivity influences not only users ’ interests, i.e., the content they own, but also their willingness to share data with others. All these factors can have a significant effect on the capacity gains achievable through opportunistic contacts. This paper’s main contribution is in developing a tractable model for estimating such gains in a content update system, where content originates from a server along multiple channels, with blocks of informatio

[22] E.L.Lawler, J. K. Lenstra, A. Rinnooy-Kan and D. Shmoys, The Traveling Salesman Problem: A Guided Tour of Combinatorial

in Space III, 1992, pp. 401-408