カイケイ エンフォースメント ケンキュウ ニ オケル リロン ブンセキ ノ カダイ

経営者や監査人の不正が発生する構造的な問題点を突き止め，それを改善する会計エンフォースメント制度を提案するためには理論分析が必要である。この論文では，会計エンフォースメントにおける理論分析を扱う論文を取り上げ，そのモデルについて比較検討する。また本論文では会計エンフォースメントの持つ経営者と会計監査人の不正を監視するという側面に注目したBrown et al.（ 2014）にならい，会計エンフォースメントを監視，規制の制定，評価基準，情報提供，ペナルティ，機関の規模の6 つの要素に分類し，各論文がこれらの要素についてどのように議論や分析を行っているかについて検討している。その結果として従来の会計エンフォースメントにおける理論分析では，会計エンフォースメント機関をプレイヤーとする理論分析が行われていないことを指摘している。I compare four papers dealing with theoretical models analyzing accounting enforcement. To identify problems underlying management and auditor fraud, and to devise accounting enforcement to address such problems, theoretical analyses are necessary. Following Brown et al. (2014), I focus on fraud detection in accounting enforcement and classify accounting enforcement into six elements, namely, monitoring, the power to set standards, reviewing, providing information, penalties, and level of resourcing. I find that existing theoretical research on accounting enforcement overlooks the fact that accounting enforcement agencies are active players.論

Moment Tensor Analysis of Acoustic Emissions Induced by Laboratory-based Hydraulic Fracturing in Granite,

Moment Tensors of hydraulically induced AEs: Hydraulic fracturing is an important technique in the development of enhanced geothermal systems and unconventional resources. Although the fracture modes induced by hydraulic fracturing influence the recovery efficiency of the resources, the current understanding of this relationship is insufficient. In this study, we considered the acoustic emissions (AEs) induced during hydraulic fracturing under uniaxial loading conditions in the laboratory, and applied a moment tensor analysis by carefully correcting the coupling condition and directivity of AE transducers. Experiments were conducted for two types of Kurokami–jima granite samples: those with a rift plane perpendicular (Type H) or parallel (Type V) to the expected direction of fracture propagation (i.e. along the loading axis). In the experiments, both sample types experienced a significant number of shear, tensile and compressive events. The dominant fracture mode for Type H samples is found to be tensile events in which the fracture plane is parallel to the loading axis, whereas for Type V samples, shear events are dominant. This difference suggests that the dominant fracture modes induced by hydraulic fracturing are highly dependent on the relationship between the direction of fracture propagation and orientation of pre-existing weak planes

New readout and data-acquisition system in an electron-tracking Compton camera for MeV gamma-ray astronomy (SMILE-II)

For MeV gamma-ray astronomy, we have developed an electron-tracking Compton camera (ETCC) as a MeV gamma-ray telescope capable of rejecting the radiation background and attaining the high sensitivity of near 1 mCrab in space. Our ETCC comprises a gaseous time-projection chamber (TPC) with a micro pattern gas detector for tracking recoil electrons and a position-sensitive scintillation camera for detecting scattered gamma rays. After the success of a first balloon experiment in 2006 with a small ETCC (using a 10$\times$10$\times$15 cm$^3$ TPC) for measuring diffuse cosmic and atmospheric sub-MeV gamma rays (Sub-MeV gamma-ray Imaging Loaded-on-balloon Experiment I; SMILE-I), a (30 cm)$^{3}$ medium-sized ETCC was developed to measure MeV gamma-ray spectra from celestial sources, such as the Crab Nebula, with single-day balloon flights (SMILE-II). To achieve this goal, a 100-times-larger detection area compared with that of SMILE-I is required without changing the weight or power consumption of the detector system. In addition, the event rate is also expected to dramatically increase during observation. Here, we describe both the concept and the performance of the new data-acquisition system with this (30 cm)$^{3}$ ETCC to manage 100 times more data while satisfying the severe restrictions regarding the weight and power consumption imposed by a balloon-borne observation. In particular, to improve the detection efficiency of the fine tracks in the TPC from $\sim$10\% to $\sim$100\%, we introduce a new data-handling algorithm in the TPC. Therefore, for efficient management of such large amounts of data, we developed a data-acquisition system with parallel data flow.Comment: 11 pages, 24 figure

Direct measurement of spectral shape of Cherenkov light using cosmic muons

The spectral pulse shape of Cherenkov lights was directly measured by using cosmic muons. The observed decay times for early and late timing were 5.0 and 5.2ns, respectively. They were actually shorter than the time of scintillation lights which were also measured as 9.3ns and 9.2ns, respectively. However we could not see the difference of the rise time between scintillation and Cherenkov lights. This was due to the slow response of our DAQ equipment, photomultiplier and FADC digitize

Precise pulse shape measurement of Cherenkov light using sub-MeV electrons from Sr-90/Y-90 beta source

The precise spectral pulse shape from Cherenkov lights was directly measured by using sub-MeV electrons from 90Sr/90Y beta source. The observed shape was clearly different from the shape of scintillation light. The pulse rise and fall （decay） time for Cherenkov light were 0.8 ns and 2.5 ns, respectively. They were actually shorter than those times of scintillation light which were also measured by 1.6 ns and 6.5 ns, respectively. This clear Thisclearclear difference of rise time will be used for the pulse shape discrimination in order to select PMTs which receive Cherenkov lights, and the topological information due to Cherenkov light will be used for the reduction of backgrounds from 208Tl beta decay which should be major backgrounds observed around Q-value （3.35MeV）of 96Zr neutrinoless double beta decay

Development of a large area gas photomultiplier with GEM/μ\muPIC

We are developing a new photon detector with micro pattern gaseous detectors. A semitransparent CsI photocathode is combined with 10cm$\times$10cm GEM/$\mu$PIC for the first prototype which is aimed for the large liquid Xe detectors. Using Ar+C$_2$H$_6$ (10%) gas, we achieved the gas gain of $10^5$ which is enough to detect single photoelectron. We, then, irradiated UV photons from a newly developed solid scintillator, LaF$_3$(Nd), to the detector and successfully detected single photoelectron.Comment: Poster presentation at ICHEP08 Philadelphia, USA, July 2008. 3 pages, LaTeX, 4 eps figure

Direction-sensitive dark matter search results in a surface laboratory

We developed a three-dimensional gaseous tracking device and performed a direction-sensitive dark matter search in a surface laboratory. By using 150 Torr carbon-tetrafluoride (CF_4 gas), we obtained a sky map drawn with the recoil directions of the carbon and fluorine nuclei, and set the first limit on the spin-dependent WIMP (Weakly Interacting Massive Particles)-proton cross section by a direction-sensitive method. Thus, we showed that a WIMP-search experiment with a gaseous tracking device can actually set limits. Furthermore, we demonstrated that this method will potentially play a certain role in revealing the nature of dark matter when a low-background large-volume detector is developed.Comment: 9 figures, accepted for publication in Phys. Lett.