49 research outputs found
Politicization of Risk in Military Acquisition: A Case Study of the A-12 Program and its Termination
No full textWhy and how does a risk once accepted raise a political problem in a way that affects the consequence of a policy? To answer these questions this article focuses on the interactive change of political context and risk perception. A changing political context may develop a gap in risk perception among actors and vice versa. This gap distorts the initial consensus on risk acceptance affecting the consequence of policy; here this process is referred to as the politicization of risk. Applying this perspective this article examines the process in which the A-12 aircraft acquisition program of the U.S. Navy was adopted as policy but eventually terminated due to technical and political mismanagement of risk. The analysis indicates that risk propensity is influenced not only by personality and political institutions as some scholars point out but is also changed by an interaction between political context and actors’ perception. In the case of the A-12 program a perception gap between the executive and legislative branches caused a politicization of risk and consolidated a risk-averse context which led to the termination of the program. 政治過程において一旦受け入れられたリスクは、なぜ、いかにして政治的問題を提起し、政策の帰結に影響を与えるようになるのか。本稿ではこの問題を、アクターのリスク認識と政治的コンテクストが相互作用的に変化する過程に着目することで明らかにしていく。この過程において生じる認識ギャップは、リスク受容について当初形成されたコンセンサスを歪める。その結果、一旦は潜在化したリスクをめぐる政治論争が再燃し、政策そのものにも変更を迫ることになる（本稿ではこれを、リスクの「政治化」と呼ぶ）。本稿ではこのような観点から、米国海軍のA-12艦載攻撃機開発プログラムの事例を分析し、リスクをめぐる行政府、立法府間の認識ギャップがリスク問題の再検討を促した結果、リスクを嫌忌する政治的コンテクストが強化され、高い軍事的要請にもかかわらずプログラムが中止されるに至った経緯を明らかにしている。departmental bulletin pape
<Book Review> The Diffusion of Military Power: Causes and Consequences for International Politics by Michael C. Horowitz
No full textIn Diffusion of Military Power: Causes and Consequences for International Politics Michael C. Horowitz presents his ‘adoption-capacity theory’ to explain why military technology and doctrine on the cutting edge are diffused differently in a given international system and how it influences the mechanism of power transition. In his theory Horowitz focuses on the state’s adoption-capacity determined by financial intensity and organizational capacity. This is valuable as a complementary approach to traditional models that emphasize geopolitical factors. Although his empirically tested argument has some problems with regards to omitted variables and applicability to current diffusion matter it offers an important springboard for further discussion on the diffusion of military innovation both in academic and policy contexts. 要旨 革新的な軍事技術やドクトリンが各国においてどのように採用され、その結果として国際システムの様態にいかなる影響を及ぼすかという問題は、国際政治学における重要なテーマの一つである。ホロウィッツは本書において、財政力と組織資本に焦点を当てた「導入能力理論（adoption-capacity theory）」を提示し、地政学的要因を重視する従来のアプローチに補完的な立場をとりつつそのメカニズムを説明しようと試みる。本書の議論は変数の解釈や現代の事例への適用についていくつかの問題を孕んでいるものの、技術革新の加速と同時に装備調達への財政的制約が高まる近年の状況下において重要な学術的議論の基盤を提供するのみならず、高い政策的関心を集めうるものである。departmental bulletin pape
How Have the U.S. Interests in Greenland Changed?: Reconstructing the Perceived Value of Thule Air Base After the Cold War
No full textStatistical properties of weighted complex networks characterized by metaweights
No full textWe propose several characterizations of weighted complex networks by incorporating the concept of metaweight into the clustering coefficient, degree correlation, and module decomposition. These incorporations make it possible to describe weighted networks depending on how strongly we emphasize weights. Using some applications to real-world weighted networks, we demonstrate that the proposed approach provides rich information that was inaccessible by previous analyses such as the degree correlation for a specific magnitude of weights or the community structure under controlling the importance of roles of the topology and weights
Scale-free property of local-world networks and their community structures
No full textThe scale-free property and community structures of complex networks formed by local events have been studied theoretically, numerically, and empirically. We showed analytically and numerically that the degree distribution function P(k) of the local-world evolving network exhibits a crossover from an exponential to power-law form by increasing the local-world size M. For M much larger than the crossover local-world size Mco, the distribution function P(k) has a power-law form for any degree k(>> 1). Below Mco, however, P(k) obeys a power law for 1 > kco. The crossover size Mco and the crossover degree kco have been also elucidated. In addition, we constructed the drug prescription network (DPN) as a real local-world network, in which the local-world subsets are definitely specified, to reveal how the local-world nature affects properties of real-world networks. We found that the community structure of the DPN strongly correlates with the local worlds
Frequency dependence of the Hall-potential distribution in quantum Hall systems: Roles of edge channels and current contacts
No full textThe spatial dependence of the Hall potential induced in a two-dimensional electron system (2DES) by AC source-drain voltage is studied theoretically in the incoherent linear transport in the strong-magnetic-field regime. The local capacitance approximation is employed in which the potential at each point of the 2DES is proportional to the induced charge at the same point It is shown that the frequency dependence of the induced charge distribution is described by three time constants, tau(e) for transport through an edge channel of the electron injected from a current contact, tau(eb) for transition between the edge channel and the bulk state, and tau(b) for diffusion into the bulk, which are quite different in magnitude: tau(e) << tau(eb) << tau(b) in the quantum Hall regime of a typical sample. These three time constants also determine how the Hall potential evolves in the 2DES after the source drain voltage is turned on. Calculated two-dimensional distribution of the Hall potential as a function of the frequency reveals that the Hall potential develops by penetrating into the bulk from source and drain contacts as well as from the edge channel
Highly strong and conductive carbon nanotube/cellulose composite paper
No full textCarbon nanotube (CNT)/cellulose composite materials were fabricated in a paper making process optimized for a CNT network to form on the cellulose fibers. The measured electric conductivity was from 0.05-671 S/m for 0.5-16.7-wt% CNT content, higher than that for other polymer composites. The real permittivities were the highest in the microwave region. The unique CNT network structure is thought to be the reason for these high conductivity and permittivity values. Compared to other carbon materials, our carbon CNT/cellulose composite material had improved parameters without decreased mechanical strength. The near-field electromagnetic shielding effectiveness (EMI SE) measured by a microstrip line method depended on the sheet conductivity and qualitatively matched the results of electromagnetic field simulations using a finite-difference time-domain simulator. A high near-field EMI SE of 50-dB was achieved in the 5-10 GHz frequency region with 4.8-wt% composite paper. The far-field EMI SE was measured by a free space method. Fairly good agreement was obtained between the measured and calculated results. Approximately 10-wt% CNT is required to achieve composite paper with 20-dB far-field EMI SE
Highly efficient enzymatic synthesis of 3'-deoxyapionucleic acid (apioNA) having the four natural nucleobases
No full textThe synthesis of the 3'-deoxyapionucleoside 3"-triphosphates (apioNTPs) having the four natural nucleobases and their enzymatic incorporation into a DNA-DNA primer-template have been tried. Therminator DNA polymerase was shown to incorporate these apioNTPs effectively giving 43mer DNA-apioNA chimera
An oligodeoxyribonucleotide containing 5-formyl-2′-deoxycytidine (fC) at the CpG site forms a covalent complex with DNA cytosine-5 methyltransferases (DNMTs)
No full text5-Methylcytosine (mC) is known to induce epigenetic changes. Ten-eleven translocation (TET) enzymes produce the further oxidized 5-substituted cytosine derivatives, 5-formylcytosine (fC) and 5-carboxylcytosine (caC). However, their roles are unclear thus far. Here, we synthesized oligodeoxyribonucleotides (ODNs) containing 5-formyl-2'-deoxycytidine and examined their interactions with DNA cytosine-5 methyltransferase (DNMT). We found that the ODN sequence containing fCpG formed a covalent complex with both bacterial and mouse recombinant DNMTs in the absence of any cofactors. The covalent bonding with DNMT suggests that the fCpG sequence in DNA may play a role in epigenetic regulation. (C) 2016 Elsevier Ltd. All rights reserved
