現在，マシニングセンタの加工条件最適化を支援するために，加工中の切削トルクを測定する技術が望まれている．特に微小径工具では，切削トルクが極小で検出が困難となり，またその細さ故に折損が頻繁に起きる．そこで本研究では，加工中の動的な微小切削トルクを測定することのできるツールホルダ型の装置を試作し，実験により微小トルクが測定可能であることを検証した．精度を向上させるために，測定精度を低下させる誤差要因を解析し，それに対する補正を行うことにより，市販のトルク計と同等の精度で計測することができた.

抄録全体を表示

In this paper, we developed a tool holder with torque sensing function in it by using a magnet coupling with magnetoresistance sensors. Cutting torque twists a tool holder against a tool chuck through a magnet coupling. We can estimate torque by estimating amount of twist. Unfortunately errors in machining and assembly of a tool holder degrade an accuracy of torque measurement. We estimated an effect of manufacturing on a measurement error and developed a technique to compensate manufacturing errors. We checked its accuracy by comparing its output signal with a torque sensor provided by Kistler. Finally we confirmed that the developed tool holder with sensing function showed almost same accuracy as a torque sensor provided by Kistler.

抄録全体を表示

Refractoriness of main and accessory fibres into Pacinian corpuscle has been measured with two impulses generated by mechanical stimuli or antidromical electrical stimuli.
1) The depression produced by a preceding stimulus of the Pacinian corpuscle, resulting from mechanical stimulus has been measured below 1 msec, and its value is smaller than transmission time from corpuscle to main fibre, and also than its of main fibre itself.
2) The absolute refractoriness of transmission from corpuscle to the main fibre is about 1. 3msec.
3) The absolute refractoriness of the main fibre itself is about 2 msec.
4) The recovery time for the complete transmission from corpuscle to the main fibre, needs 5 to 6 msec.
5) The absolute refractoriness of an accessory fibre is 2030msec.
6) The complete recovery time for C fibres needs about 200msec.
From above results we can consider that the most popular inserval of spontaneous discharge in main fibre is 5 to 6 msec and the accsssory fibres is 200msec.

抄録全体を表示

現在，マシニングセンタの加工条件最適化を支援するために，加工中の切削トルクを測定する技術が望まれている．特に微小径工具では，切削トルクが極小で検出が困難となり，またその細さ故に折損が頻繁に起きる．そこで本研究では，加工中の動的な微小切削トルクを測定することのできるツールホルダ型の装置を試作し，実験により微小トルクが測定可能であることを検証するとともに，測定精度を低下させる誤差要因の解析を試みた．

抄録全体を表示

Statistical and dynamic methods were used in the downscaling process from Global Climate Model (GCM) to Regional Climate Model (RCM). We selected the European Centre for Medium-Range Weather Forecasts model, Hamburg version 4 (ECHAM4) with 300 × 300 km resolution for A2 scenario. We focused on SE Asia domain located between 20°S to 30°N and 80°E to 135°E for 1960–2099 with wind components, temperature, geo-potential height, and specific humidity as data input in Providing Regional Climates for Impacts Studies (PRECIS) RCM analysis. The downscaling process output was 50 km resolution for 1971–2010 and precipitation, temperature, wind, relative humidity, radiation from 8 meteorological stations in Chao Phaya River Basin; Lampang, Suphanburi, Nan, Sisamrong, Takfa, Chainat, Uthong and Bangna selected and used for bias correction. Three methods, namely 1) adjusting the mean based on RCM, 2) adjusting the mean based on observation, and 3) quantile-based mapping were used. Methods were compared using observed climatic data, RCM outputs of calibration period, and RCM outputs from the validation period. RSME was found to be lower for method 2 compared to other methods implying a relatively superior technique for improving the model. As such method 2 was used to correct the PRECIS products during 2001–2009. These products are useful in the studies of impact of climate change and for early warning systems in Thailand.

抄録全体を表示

 Cloud-track-wind data, also often called SATOB data, provide an invaluable source of observational information from otherwise sparsely covered parts of the lower and upper troposphere, particularly in the tropics. SATOB data were, for the first time, collected on a global basis during FGGE. During the analysis of these data for the ECMWF Main level III-b production, some questions arose regarding apparent systematic biases in the data in and near jetstreams. In preparation for a reassimilation of parts of the FGGE at ECMWF these questions were adressed again, benefitting from the accumulated experience of global data assimilation at the Centre. Several types of diagnostics, based both on the data assimilation. scheme and independent, collocated observations were extracted and evaluated, based on the Final FGGE level II-b data from December 1978.
 The biases were found to be negative, underestimating the windspeed, and quite systematic. All datasets from different producers that could be reliably assessed were found to suffer. The problem was most pronounced in the subtropical jetstreams, where individual wind analyses were found to be seriously deformed by too weak SATOB windspeeds, especially in areas void of other sources of data. Impact was also seen in monthly averages. In a simple calibration experiment, an attempt was made to reduce the biases. The result showed a great impact of the calibration, indicating both the importance of SATOB data and the risks associated with their systematic biases.

抄録全体を表示

Plants are frequently exposed to limitations in oxygen availability during their lifetime. During evolution, they have developed a number of physiological and morphological adaptations to tolerate oxygen and other stress conditions. These include regulation of growth by gene expression and ATP generation. The regulation of nuclear genes after hypoxia and anoxia is well studied; however, the regulation of mitochondrial genes in response to oxygen stress has not been characterized to date. Therefore, we have established an Arabidopsis mitochondrial genome-specific microarray that accommodates probes for all mitochondrial DNA-encoded genes and conserved open reading frames. Our analysis showed an up-regulation of mitochondrial transcripts in Arabidopsis roots after 48 h of hypoxia. Since no significant difference was detected in the expression of mitochondrial RNA polymerases or the mitochondrial DNA content per cell, we propose a transcriptional mode of induction of mitochondrial gene expression under hypoxia.

抄録全体を表示

日本海南部沿岸域における完新世初～中期の暖水系生物相と対馬海流の挙動との関係を理解するために, 出雲平野北西部と鳥取沖でそれぞれ採取された柱状試料HS02とGH87-2-308について, 浮遊性有孔虫化石を検討した. GH87-2-308における暖水系種Globigerinoides ruber の産出傾向は, 約8,300～8,000年前と約7,300～6,800年前の2つの時期に, 対馬海流の影響が強かったことを示す. 本種はHS02でも, 暖水系底生生物相が産出する約7,800年前の層準で見出される. 日本海のより沖合 (たとえば隠岐堆) の研究事例では, 暖水系微化石の産出は約7,300年前に普遍的なものの, 同様な普遍的産出は約8,300～7,800年前では不明瞭である. よって, 約8,300～7,800年前の対馬海流の影響は, 沿岸域で顕著に現れ, それが当時の山陰地方沿岸域における暖水系生物相の産出傾向を左右したと考えられる.

抄録全体を表示

　海洋生物化石の¹⁴C年代をより一層正確な暦年代に較正するためには，¹⁴C年代較正プログラムにΔR（試料採取地点の¹⁴C年代の補正値）を入力しなければならない。Omoto et al.（2010）が報告した北海道オホーツク海沿岸のΔR（－158 yr）は，太平洋沿岸や日本海沿岸のΔR（34 yr～345 yr）と乖離している。この結果を踏まえて北海道オホーツク海沿岸のΔRを新たに決定するため，斜里町のオシャマップ川遺跡とトーツル沼1遺跡から木炭と貝化石をペアとする合計4組の試料を収集してAMSによる¹⁴C年代測定を行い，Marine20にもとづきΔRを計算した。その結果，オシャマップ川遺跡III層のΔR（1σ）は－94±60 yrとなり，またトーツル沼1遺跡のPit 2から55±46 yrと135±45 yr（平均95±64 yr）のΔRが得られた。新たに決定されたΔRは，かつてトコロ貝塚の試料にもとづき決定された－158 yr（Marine20にもとづき計算すれば－323±42 yr）とは大きく異なる。

抄録全体を表示

 フィリピン，南ルソンのイロシンカルデラ内の地点IrBH-2で深度 50 mまでコア試料を採取し，50 cmごとに堆積物を記載した。深度 7.02～10.40 mから採取した植物片について，およそ1000～1800BPのAMS放射性炭素年代を得た。このコア試料では，ラハールや河川堆積物が多くを占めるが，上部 12 mは主として安山岩質の河川堆積物からなり，ラハール堆積物をわずかに伴う。この層準は，おそらく安山岩質の後カルデラ火山活動に対比できると考えられる。深度 12～50 mまでに12枚の降下テフラと1枚の火砕流堆積物が認められるが，そのなかの5枚の降下テフラは再堆積かもしれない。火山ガラスと斑晶鉱物の屈折率を測定したいくつかの試料は，後カルデラ火山の活動では安山岩質～デイサイト質噴出物が主であり，流紋岩質なものがわずかに伴うことを示唆する。また，流紋岩質降下テフラは，41 cal kBPのイロシン火砕流堆積物と共通した岩石記載的特徴を持ち，両者が同一のマグマに由来する可能性を示唆する。

抄録全体を表示

The 3-D information obtained from cameras' 2D images is given as a visual line by using calibrated parameter values, and we should evaluate the calibration accouracy with respect to the visual line direction error. In this paper, the visual line direction error was examined, based on an evaluation criterion where the calibrated principal point coordinates are taken as the references of the visual line. Many important caracteristics with the calibrated parameter value errors and their resulting visual line direction errors were found out by conducting a large amount of simulations under various conditions such as the depth ratios of calibration chart, and the principal distances of cameras. Fnally, the error characteristics were analytically proved, and some formulae were derived. The formulae enable us to estimate calibration errors for any calibration conditions in advance.

抄録全体を表示

Nantai volcano, northeast Japan, is a stratovolcano whose recent eruptive activity is poorly known. This paper presents the characteristics and ages of a newly discovered Holocene succession of volcanic and sedimentary units exposed at the northern sector of the present summit crater of Nantai volcano. The stratigraphic relationships and three accelerator mass spectrometry (AMS) ¹⁴C ages for eruptive products and lacustrine deposits of the northern sector of the summit crater show that Nantai volcano was active after the 15-14 cal ka BP eruption, which was thought to be the latest eruption of the volcano. After the 15-14 cal ka BP eruption, the summit crater was filled by a lake in which a water-chilled volcanic and tuff breccias (Goshinbutsunagi Volcanic Breccia) and the overlying lacustrine deposit (Nantai Lacustrine Deposit 1: NLD1) were emplaced. The ¹⁴C age of ∼ 8 cal ka BP obtained from a wood fragment in the bottom of NLD1 defines the initiation of the deposition of NLD1 in the crater lake. The crater lake dried up before 7 cal ka BP, following which a phreatomagmatic eruption occurred in the summit cater, forming Nantai-Yudonoyama Tephra (NYT). NYT is the latest recognized eruption product of Nantai volcano, and it underlies the second lacustrine deposit (Nantai Lacustrine Deposit 2) formed in the renewed crater lake. The young age of 7 cal ka BP obtained from the two charred wood stumps in NYT highlights that Nantai is an active volcano.

抄録全体を表示

A method for reconstructing a complete three-dimensional (3D) voxel model from multiple images captured during two circular motions of an object is proposed. The two circular motions include the object with a regular orientation and the corresponding reversed orientation. The shape-from-silhouette method, which constructs a voxel-based 3D model from the silhouettes of two-dimensional (2D) images, is used for the reconstruction. In general, a single camera focused on an object's circular motion cannot capture the entire object using a single fixed orientation. Thus, it is required to invert the orientation of the object at least once to capture the entire object. In this paper, a novel method for integrating two incomplete reconstructed voxel models to produce a single complete voxel model is discussed. Complex examples are provided to demonstrate the effectiveness of the proposed algorithms.

抄録全体を表示

Glaciar Perito Moreno, with an area of 258km², is located on the eastern side of the Hielo Patagónico Sur (Southern Patagonia Icefield) at about 50°29′S and 73°04′W. Currently, it terminates in Lago Argentino, thereby dividing the lake into Canal de los Tmpanos to the north and Brazo Rico to the south. The glacier has repeatedly made small advances and retreats in the 20th century; however, it can be regarded as rather stable since the 1920. Based on ¹⁴C dating of 22 wood and one organic samples, we inferred that Glaciar Perito Moreno made two Little Ice Age (LIA) advances, one at ca. AD 1650 and the other about AD 1820-50. These two dates fit very well into the general framework of the LIA of the HPS.

抄録全体を表示

濃尾平野内陸部の河成低地において採取した2本のコア堆積物を解析し，低地とその地下を構成する堆積物の特徴を検討した．2本のコアの採取地点は約280m離れているが，表層河成層の下位にみられる海成層は両コアともに類似しており，海成層が累重していた時期の堆積環境はほぼ同じだったと考えられる．河成層は約4,000 cal BP以降に堆積したが，ST1コアでは植物片の薄層を多く含む泥質堆積物で特徴づけられる氾濫堆積物が海成層を覆って厚く累重する．それに対し，ST2コアでは砂礫からなる流路堆積物が下位の海成層を侵食し，この上にST1コアと同様の氾濫堆積物が積み重なる．また，両コアの氾濫堆積物は2つの層準に極細粒～細粒砂層を挟在し，これらの砂層はそれぞれ4,000～1,400 cal BP, 1,400 cal BP以降に堆積したと考えられる．これは，両地点が砂の堆積を被る規模の洪水を少なくとも2度経験したことを示唆する．

抄録全体を表示