Vertical gates such as slide gate and roller gate are used for regulating the rate of discharge for intake structures in river and dam. These gates are classified into two types by water sealing method, namely the sealing part is upstream side or down stream side of gate.
And almost of them are used under the free flow conditions, but in some cases it is used in submerged conditions. Vibrations are not observed almost of free flow conditions in both type of sealing method.
But under the small opening of gate in submerged flow conditions, the vibration are observed in both field and model gates. This vibration is difined as self-excited oscillation and an amplitude of oscillation becomes larger from still conditions without action of external force.
This self-exciting oscillation is very interesting on the following facts, 1) it is strongly related to the nature of gate oscillation system. Such as when the spring constant becomes smaller, the amplitude of oscillation becomes larger and also oscillating zone related to the gate opening becomes wider. 2) The shape of gate lip of down stream side is also related to this oscillation, as the inclination of gate lip is larger, the oscillation occures in wide region of gate opening.
A theoretical analysis on this oscillation has been made as non linear differential equation of vibration, and the unsteady condition can be determined and its result can show the good relations between the data from the model test.

抄録全体を表示

A discrete vortex method combined with the source distribution method was applied to the flow analysis around a rectangular cylinder accompanied by through-flow. The effects of kinematic viscosity ν on drag coefficient and Strouhal number were investigated. The value ν of 0.00001m²/s was the most appropriate one under our conditions. The ratio of vertical to horizontal length of a rectangular cylinder was changed as a calculational parameter. The drag coefficient C_D was in agreement with the reported results. The calculations of the through-flow into the rectangular cylinder were carried out under the same conditions as those in the experiments in a two-dimensional water pool. The calculated and experimental values were satisfactorily in agreement. Consequently, it is shown that our numerical method is very useful in calculating the through-flow into the body.

抄録全体を表示

Field trip to Daytona Beach, Ponce de Leon Inlet and New Symrna Beach in Florida was made in September 1996. Past beach changes and present results of field observation were compared around Ponce de Leon Inlet, where sand bypassing was once carried out. It was revealed thaton the downcoast of this inlet beach erosion is now underway to cause beach scarp along the sandy shoreline. Eroded coast is protected by seawall, but foreshore width is too narrow for recreational usage, implying the necessity of future sand nourishment. Beach access at many coasts in Florida is compared with the situation in Japan and future improvement method in Japan is proposed.

抄録全体を表示

銀行窓販による変額年金市場は，規制緩和により急速に拡大し，リーマンショックに始まる金融危機のなかで消滅していった。この間の主要なプレイヤーの活動および業績の推移を分析することで，市場が拡大，縮小，消滅するまでの経緯をたどる。
変額年金販売の成功は，解禁直後に販売者に専用商品を提供するビジネスモデルを構築したこと，大幅な市場拡大は，ペイオフの解禁時に元本保証付変額年金を開発したことにあったと考えられる。
一方，市場の急激な縮小は，消費者が購入を控えたのではなく保険会社が販売を自制したためと考えられる。この間，商品の特性は大きく変わることなく，変わったのは販売する保険会社であった。
金融危機のなかで，銀行はリスクのほとんど無い元本保証付変額年金の販売継続を望んだと思われるが，一方で健全性が悪化した保険会社は，銀行との関係において，商品を改訂したり販売を抑制したりするのではなく，販売を停止することを選択した。これが変額年金市場消滅の要因であると考える。

抄録全体を表示

We have been developing the JINS MEME, an eyewear with a capability to detect eye and body movements. The horizontal and vertical EOG (electrooculogram) signals are measured and amplified with three metal dry electrodes placed near nasion and both sides of rhinion, of which positions correspond to the bridge and nose pads of eyewear, respectively. The user's mental states like drowsiness, fatigue, or interest to objects can be identified by the movements and blinking of the eyes extracted from the measured EOG. And the six-axis motion sensor (three-axis accelerometer and three-axis gyroscope) mounted in the eyewear measures the body motion. As the sensor located near the head is on the body axis, this eyewear is suitable to measure user's movement or shift of center of gravity during physical exercise with a high precision. The measured signals are used to extract various events of eye and body movement by the mounted MPU chip, or can be transmitted to the external devices via Bluetooth communication. In this presentation, the outline of the eyewear is introduced and some possible applications are shown.

抄録全体を表示

The optokinetic response (OKR) of the eye is induced to follow a large field visual motion. The gain of the OKR (eye velocity / visual motion velocity) is about 0.6 at 1/8Hz in naive goldfish. If the same periodic visual stimulus is given continuously, the OKR gain increases up to 1.0. In addition to the gain increase, goldfish were found to acquire a ‘predictive’ OKR behavior that was named period tuning (PT). Thus OKR velocity decreased before the change in OKS direction as if predicting the OKS timing (Marsh & Baker, 1997). Even if the animal is exposed to complete darkness after the acquisition of PT, its eye velocity follows the similar trajectory to that during training for a while without any visual stimulation. This eye movement in the dark may share a common mechanism with optokinetic after nystagmus (OKAN), and considered to reflect characteristics of the velocity storage mechanism (VSM). To investigate the possible relationship between PT and VSM, we carried out a series of behavioral experiments in goldfish, carp, medaka, zebrafish, and human. We demonstrate that ability to acquire PT is highly dependent on OKAN. This result suggests that VSM is a key mechanism for PT.

抄録全体を表示

Our previous studies have shown that motor learning is acquired faster with greater memory retention in hyper-gravity (G) environments for both goldfish and humans. This learning occurred during prism adaptation in humans, and oculomotor neural integrator (NI) adaptation in goldfish in which hyper-G was created by centrifugation. An augmented gravitation input would significantly increase vestibular input to both the goldfish and human cerebellum, in particular the vestibulocerebellum (VCB). Thus, an increase in Purkinje cell (Pkc) activity forms the basis of our working hypothesis for accelerated motor learning under hyper-G. In that event it should be possible to accelerate motor learning by using another stimulus that up-regulates Pkc activity as has been observed in the primate VCB (flocculus) in which Pkc exhibit higher dc firing rates in light than in dark. We conducted an experiment in goldfish using a white point to a black background (Darker stimulus) or black spot on a white background (Brighter stimuli). After two hours the learning curves of NI adaptation were compared and the brighter stimulus was found to induce significantly faster learning than the darker stimulus.

抄録全体を表示

高齢者が自立して自身の自宅で過ごすためにはインテリアの活用が有効ではないか，という仮説からいつもいる居場所である居室の床に置かれたモノに着目した。 現場でのヒアリングから一番身近な環境である高齢者の居場所の床に置かれたモノとモノの高さも加味した考察と，モノと床との関係性からコレスポンデンス分析を行い，高齢者の特徴や着眼点を見出し , 安全・安心・健康から本質的な高齢者の特徴を探りインテリアのポイントとなる9点を抽出した。

抄録全体を表示

本研究は，高齢者の自宅の居場所にあるモノに着目した。360度カメラに映し出されたモノと，コレスポンデンス分析からモノとモノとの関係性を探ることでインテリア活用の可能性を見出し，高齢者自身が少しでも長く自立・自律できるようにすることが目的である。現状と分析より，1.自分仕様への工夫の道筋，2.抗加齢の対策，3.高齢者の特性を支援の3点の要因を見出した。

抄録全体を表示

The aim of this study is to propose a method of evaluating for level of driver’s mental workload by using machine learning methods. In order to examine parameters related to visual behavior effective for evaluating driver's mental workload in driving, we measured EOG and head movements during simulated driving. In the experiment, we attempted to distinguish the "low mental workload" condition from "high mental workload" condition by using various machine learning methods, such as Adaboost, RBF networks and SVM on data related to EOG and head movements. Through cross-validation using the data from one participant as test data and data from the others as training data, the Adaboost method was determined to have the highest correct discrimination rate (over 85%). These results suggest the possibility of evaluating mental workload while driving.

抄録全体を表示

For fire evacuation safety in office buildings that include small rooms and where many occupants cannot directly see fire or smoke, fire alarms play a significant role in situational awareness and decision-making pertaining to evacuation. We conducted experiments to examine how individuals feel sound of fire alarms at different size of rooms using a mobile VR head-mounted display. We revealed the effect of early warning and evacuation-directive voice alarms installed at different places, e.g., a large office room and a small meeting room. In addition, we discussed the awareness process of occupants considering the configuration of smoke detection system.

抄録全体を表示

※本記事に抄録はありません。

抄録全体を表示