Long-term performance prediction of oscillating wings for assisting ship propulsion at actual seas

In order to raise ship energy efficiency, the possibility of wave energy recovery by a pair of coil-spring connected oscillating wings for assisting ship propulsion in waves is investigated. A frequency domain hydrodynamic model based on potential theory is established to predict the effect of the oscillating wings on the ship in regular waves, in terms of reducing wave-added resistance and improving seakeeping performance. The proposed linear model is suitable for short-term prediction based on conventional spectral analysis techniques, thus making it possible to evalute the long-term performance of oscillating wings for assisting ship propulsion at actual seas based on wave statistics. A sample containership is adopted to study the performance of the proposed concept. The results show that the oscillating wings can effectively reduce the added resistance of the ship at actual seas. The feasibility of this green ship technology is proved.     

九江学院校友资源利用问题及成因分析

九江学院在校友资源利用中存在校友组织机构和工作运作问题、校友信息管理问题、校友资源利用形式和服务问题及校友意识和观念问题等,本文从根本原因、重要原因、基础原因和具体原因进行了分析。     

一种基于手机定位数据的出行行程识别方法

提出并实现了一种基于手机定位轨迹数据的出行行程识别方法.通过速度对轨迹点进行划分,将低于一定速度阈值以下的轨迹点合并为候选停留位置,再利用距离阈值和时间阈值对候选停留位置进行合并,从而确定出真正的停留点,继而自动统计出行次数和出行时间.该方法解决了手机定位数据的定位漂移和抖动的问题,行程识别精度高,识别结果可为交通规划工作提供相关数据,并具有比传统交通调查方法更低的成本和更短的数据更新周期.     

排尿性晕厥合并蛛网膜下腔出血一例

<正> 病历摘要:刘某,男,28岁,住院号86038。1984年6月某日午夜小便时,突然头晕,眼花,下肢发软,随即晕倒在厕所,持续约1分钟。检查无异常发现。1986年3月8日晨起小便时又发作一次。6小时后头痛剧烈、恶心、呕吐、有谵妄、嗜睡,来院就诊。查体:面额皮肤损伤,前额部有5×5cm的血肿,左颞部有4×6cm大小的血肿,颈强直,眼底检查视网膜有片状出血,头颅正侧位片正常,心电图正常,脑电图双额、左顶导联慢波增多,腰穿为均匀血性脑脊液,红细胞100万/mm~3,压力侧卧位150mmH_2O,诊断为蛛网膜下腔出血。临床处理:止血敏4.0+10％葡萄糖500ml静脉滴注,20％甘露醇250ml静脉快速滴注,肌