Multiplication and division of decimal fraction is one of the most difficult contents for 5th graders in the primary school. This study focuses on the division of decimal fraction, especially on the generalization from quotitive division to first application of ratio. The purpose of this study is to clarify the understanding process in generalization of quotitive division, especially the factors of difficulties in understanding the division of decimal fraction and the factors for overcoming the diffuculties. The main results are folloing; 1. The generalization of quotitive division is made by extending the idea of 'measurement'. 2. In the generalization, it is effective to use the operative material that can generalize the idea of measurement and that function as the semi-concrete material for number-line expression. 3. The primitive model on quotitive division include the properties of 'quotient is integer' and 'dividend is larger than divisor'. 4. Children feels difficulties in such situations that quotient is decimal fraction and that dividend is smaller than divisor. These situations are related with primitive model. 5. The stages that the idea 'how many times' is abstracted from how many pieces 'are folloing; (a) The idea of 'how many times' is primitively constructed in such a division that dividend is larger than divisor and quotient is decimal fraction. (b) The idea of 'how many times' is realized in such a division that dividend is smaller than divisor. (c) The merit of the idea of 'how many times' is realized when all division of decimal fraction is conceived by the idea.

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Recently, in situ stress measurements have been carried out in Japan by various methods. Measured stresses, however, are apt to be different from regional tectonic stress field, because of such disturbing factors as topography, geological structure, material properties of rocks, and so on. Since the measurements are made at merely shallow sites, topographic effects on tectonic stress field are expected to be larger than other factors. Especially in mountainous area, they may become considerable.
In order to estimate topographic effects, a three-dimensional finite-element analysis is applied to some simple models, which represent mountainous area, on the assumption of homogeneous elastic properties. Furthermore, to geographically realistic models around measuring sites, the same analysis is applied.
The results show that (1) at relatively shallow points, stresses affected by topography are generally different from regional stress acting around the model, (2) therefore, measured stress obtained at shallow sites should be put in a topographic correction, but that (3) such topographic effects become negligible beneath the depth comparable to an amplitude of topographic undulation.

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本稿の目的は，3つの概念変容

を視点として，教科書での取り扱いの理論的背景を検討するとともに，から導かれる指導への示唆を得ることである．小数の乗法の指導を3つの概念変容に位置付けた．その結果，Posnerら(1982)では，倍の考えによる場面が有効であること，Hashweh(1986)では，累加の考えによる意味(個数のいくつ分)と割合の考えによる意味の対比が必須であること，Tsai (2000)ではでは90×3.4のような導入場面よりも，純小数の乗法が臨界事象として重要であることの示唆を得た．

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An “8-element-gauge” method is one of the stress relief techniques for the in situ stress measurements. Using this method, the measurements have been carried out at twelve sites by the Research Group for Crustal Stress in Western Japan. During the in situ processes and the data analyses for these measurements, many problems have been encountered. These problems were investigated in detail and important ones were settled. Hence the “8-element-gauge” method was significantly improved. Based on the results of the investigations, the stress values were revised into more reliable ones. In addition, characteristics of this method were examined in detail. The examinations show that the stress values are unavoidably affected by systematic errors associated with distinctive eigen vectors of the Jacobian matrix of the observation equation, unless certain conditions, such as properties of rocks, are satisfied. They also show that the stress values for several sites are suspected to include considerable amount of these errors.

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火星大気の鉛直対流の基本的な特徴を把握することを目指し, 3 次元非静力学大気を新たに開発し数値実験を行った. 方程式として準圧縮系方程式を用い, 乱流拡散係数は 1.5 次のクロージャ, 下部境界からの熱フラックスはバルク法で与える. 予備的な実験として, 放射過程は陽には計算せず, 鉛直 1 次元放射対流平衡から予想される対流加熱量に等しいだけの冷却を水平一様に与えて対流を生成することを行った. 得られた統計的平衡状態における対流場について報告を行う.

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We have developed a three-dimensional, clothed human thermal model for prediction of physiological response and micro-climate within clothing to thermal environments. The model is a coupled simulation system of the human thermal model and the clothing thermal model. It can simulate heat and mass transfer processes including moisture sorption of fabric. The performance of the model was experimentally verified. The following results were obtained : (1) The model predicted skin temperature distributions, and the micro-climate within clothing basically agreed with the experimental data. (2) Both model prediction and experimental data for the same thermal conditions showed that the skin temperature of the clothed body parts was higher than that of the corresponding body parts in nude condition, as well as the skin temperature of both the hands and the feet.

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Recently a lean-rich combustion is drawing attention as a way to decrease the level of NO_x. But the flame structure and NO_x formation process of the lean-rich flame in the unsteady-state was not made clear sufficiently. So we performed the numerical analysis in the unsteady-state in which we took the NO formation mechanism into the consideration by using the Skeletal Chemistry combined with a part of GRI-mech. And we found that thermal NO is generated not only in the high temperature region formed in the downstream of the rich flame, but also in the swell formed in the downstream of the lean flame. In the swell formed in the downstream of the lean flame, the chemical reaction is occurred actively due to the fluctuation of lateral flow that carries CH₄. The faster the lateral flow is, the larger NO mole production rate becomes.

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In general, analysis of quasi-elastic neutron scattering spectra needs some mathematical models in its process, and hence the obtained result is a model dependent. Model-dependent analysis may lead misunderstandings caused by inappropriate initial models or may miss an unexpected relaxation phenomenon. We have developed an analysis method for processing QENS data without a specific model, which we call as mode-distribution analysis. In this method, we supposed that all modes can be described as combinations of the relaxations based on the exponential law. By this method, we can obtain a distribution function B (Q, Γ) which we call the mode-distribution function, to represent the number of relaxation modes and distributions of the relaxation times in the modes. We report the first application to experimental data of liquid water. In addition to the two known modes, the existence of a relaxation mode of water molecules with an intermediate time scale has been discovered.

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本論文は Heydari Jafar の論文を拡張して議論を進める．つまり，その

は補充サイクルの在庫管理で，非対称情報を考慮にした 1 つの販売者と 1 つの購入者からなる 2-垂直型 SCM（サプライチェーンマネジメント）について議論する．ここで，需要は確率変数で，特に，リードタイム中は正規分布の確率変数である．このとき，購入者が安全在庫を確保してリードタイム中の需要をできるだけ満たし，妥当性のあるサービスレベルを提供する連続的在庫管理システムを用いる．そのにおいて，販売者に対しては，補充サイクルにおける時間依存型価格割引を，購入者に対しては，自分自身の最低限要求する意思決定量を満たすを提供すると，その結果，販売者も購入者も共に Win-Win関係を築くことができる．また，我々のが，スクリーニングゲームに適用すれば，同じ結果を示すこともできる．

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In situ stress measurements have been carried out by an “8-element-gauge” method which is one of the stress releasing methods. Several problems remain unsolved in the techniques of measurement and analysis. Their causes are exactly investigated and the accuracy of the stress value estimated is discussed in the present article.
Data employed for estimating the stress value involve systematic errors. Among them, errors in strain sensitivity matrices and those in rotational angles which determine the angles between each strain gauge and boreholes are predominant.
In order to reduce the systematic errors, the strain sensitivity matrix is recalculated and the rotational angle is corrected. Results obtained are compared with ones previously determined. The following conclusions are obtained as for the eight sites where the Research Group for Crustal Stress in Western Japan measured in situ stresses.
(1) Vertical stresses at a few sites previously determined are significantly underestimated, whereas the present ones can be explained by the gravity loading and topographic effect.
(2) Average horizontal stresses as well as maximum horizontal shear stresses vary by their corrections and are propotional to the depth from the ground surface, except for those at Ohtani mine.
The accuracy of the stress values obtained by the “8-element-gauge” method is several MPa for the measurements using two boreholes and a few MPa for ones using three boreholes, if the conditions of the measurements are the same as those at eight sites described above.

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Efficiency of ensemble experiment is examined for the purpose of describing the time development of tropical atmospheric response to a sea surface temperature (SST) anomaly. An ensemble experiment with the test cases of 200 is carried out by the use of a simplified atmospheric general circulation model (AGCM). The surface boundary condition is idealized to have a local warm SST area placed on the equator of a sphere covered with an SST distribution symmetric around the equator and zonally uniform (“aqua-planet”).
It is shown that the ensemble mean operation effectively reduce the small-scale random noise caused by precipitation activity and the noise known as intraseasonal oscillation. It is demonstrated that the time-development of planetary scale responce to the warm SST area can be clearly extracted by the enesemble mean operation. It is found that the ensemble size of at least 64 is required to extract the time-development of pressure field.

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Aztreonam (AZT)1) は米国スクイブ社で開発された単環系β-ラクタム構造を有するモノバクタム系抗生物質でPseudomonas aeruginosaを含むグラム陰性菌に対し強い抗菌力を有し, 且つ各種β-ラクタマーゼに極めて安定である(Fig. 1)。
抗生物質の経胎盤移行に関するPharmacokineticsは周産期領域感染症の治療上極めて重要であるが, すでに我々はAZTの臨床研究成果をふまえ, 本剤の妊娠ヒツジ及び妊娠37～42週の妊産婦における母体血中濃度並びに経胎盤移行濃度を検討した2)。
その結果, AZTは妊娠後期例において正常健常人とほぼ同様な血中濃度推移を示し, 又, 種々のセフェム剤と類似する胎盤通過性が認められ, AZTのin vitroにおける抗菌力から推察して, 周産期感染症のうち重要な位置を占めるグラム陰性菌感染症に対する臨床的有用性が示唆された。
一方, 胎児奇形の成立に関与すると思われる薬剤の妊娠初期における胎児・羊水への移行に関する研究は非常に少ない3～5)。
今回, 妊産婦におけるAZT使用時の有効性並びに安全性に関する研究の一環として, 妊娠初期例における母児間移行すなわち胎芽 (児) 並びに羊水への移行に関する検討を行い, 若干の成績を得たので報告する。

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Kinetics of^99mTc-GSA was compared by two different compartment modes, one is linear 1 compartment model and the other is nonlinear 5 compartment model. The subjects consisted of 15 patients, including 14 patients with liver cirrhosis or chronic hepatitis and 1 patient with normal liver. Both model parameters showed a good correlation with the ratio of^99mTc-GSA binding to receptor and the total injected^99mTc-GSA, estimated by whole body scan. Hepatic clearance (K_u) and the ratio of he-patic clearance and total excretion rate (K_u/K_e) by linear model were well correlated with the maximal removal rate by nonlinear model. On the other hand, K_uand K_u/K_eshowed a poor correlation with the hepatic blood flow. It was concluded that the parameters by linear model chiefly reflect the amount of receptors in the liver.

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金属資源の安定的利用を図るための方策の一つにリサイクルがあり，その際重要となるのが国内に既に存在するストックとしての「都市鉱山」である。マテリアルフローを用いた試算では，たとえば，コバルトは6年分，タングステンは7年分，ネオジムは5年分程度が市中の製品中に含まれた形でストックされている。分散的な一次処理 (前処理＝濃縮) と備蓄のシステムなどを組み合わせることで，有用資源を含む使用済み製品等を活用して，新たな資源を輸入せずとも定常的に資源を使い回していく社会に近づけることができる。一方，人間1人に必要とされるベース金属の資源量は，経済発展レベルに応じて増加するが，究極的には一定の値に落ち着く傾向にある。これに基づき，地球規模でみて人類に必要となる金属資源量を推計し，埋蔵資源量と比較することで，どんなタイミングでどのようなリサイクルレベルが必要とされるかの示唆を得ることができる。

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