Spatiotemporal Analysis of Groundwater Recharge Trends and Variability in Northern Taiwan

In this study, the base flow estimation method was used to assess long‐term changes of groundwater recharge in Northern Taiwan. The Mann‐Kendall test was used to examine the characteristics of the trends. This was followed by trend slope calculation and change‐point analysis. The annual groundwater recharge was found to exhibit a significant upward trend for the Fushan and Hengxi stations (Tamsui river basin). On the other hand, the Ximen Bridge station (Lanyang river basin) recorded a significant downward trend. Calculations showed that the rate of change for the Fengshan and Touqian river basins was small (less than 10%). However, that for the following stations was greater than 30%: Fushan, Hengxi, Ximen Bridge, and Niudou (also in the Lanyang river basin). The results of the change‐point analysis further indicated a significant change‐point for the annual recharge at Fushan, Hengxi, and Ximen Bridge stations in 1999, 1983, and 2001, respectively. The findings can be used for regional hydrological studies and as reference for water resource planning

WRIST : Watch-Ring Interaction and Sensing Technique for wrist gestures and macro-micro pointing

Funding: Next-Generation In-ormation Computing Development Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT (NRF-2017M3C4A7066316) and Institute of Information & communications Technology Planning & Evaluation (IITP) grant funded by the Korea government (MSIT) (No.2019-0-01270, WISE AR UI/UX Platform Development for Smartglasses).To better explore the incorporation of pointing and gesturing into ubiquitous computing, we introduce WRIST, an interaction and sensing technique that leverages the dexterity of human wrist motion. WRIST employs a sensor fusion approach which combines inertial measurement unit (IMU) data from a smartwatch and a smart ring. The relative orientation difference of the two devices is measured as the wrist rotation that is independent from arm rotation, which is also position and orientation invariant. Employing our test hardware, we demonstrate that WRIST affords and enables a number of novel yet simplistic interaction techniques, such as (i) macro-micro pointing without explicit mode switching and (ii) wrist gesture recognition when the hand is held in different orientations (e.g., raised or lowered). We report on two studies to evaluate the proposed techniques and we present a set of applications that demonstrate the benefits of WRIST. We conclude with a discussion of the limitations and highlight possible future pathways for research in pointing and gesturing with wearable devices.Postprin

Structural Analysis and Optimum Design of a Low-Floor Electrical Bus Chassis

本文研究低地板電動大客車底盤之結構分析，並提出對於低地板電動大客車底盤的結構設計與最佳化之方法，以改良靜態結構特性。藉由靜態有限元素分析方法分析大客車底盤的結構特性，本研究對大客車底盤所考慮的靜態有限元素分析包括全負載應力、彎曲剛性及扭矩剛性分析。更改設計的目地是為了以最小重量來提升大客車底盤的強度和剛性，藉由兩階段最佳化來改良複雜的大客車底盤結構。在第一階段最佳化，選取在少數高應力集中位置周圍的元件，接下來計算相關的元件厚度對於被選取元件的應力和重量的敏感度，選取具有較高的應力對重量之敏感比例的元件厚度做為設計變數，然後執行結構最佳化以藉由最小的上升重量來降低高應力集中區域；在第二階段最佳化，選取不在高應力集中位置周圍的較厚元件，接下來計算相關的元件厚度對於被選取元件的剛性和重量的敏感度，選取具有較低的剛性對重量之敏感比例的元件厚度做為設計變數，然後執行結構最佳化來減低底盤重量並保持改良後的強度和原來的剛性；最後，比較原來的和改良的底盤結構的靜態結構特性，並顯示出改良後的底盤為較佳的結構設計。This paper studies the structural analyses of a low-floor electrical bus chassis and presents a method for structural design and optimization of a low-floor electrical bus chassis for improving static structural characteristics. The structural characteristics of the bus chassis are analyzed by static finite element analysis method. The static finite element analyses considered in this research include full-loaded stress, bending stiffness and torsional stiffness analyses for the bus chassis. The redesign purpose is to increase the strength and stiffness of the bus chassis with minimum weight. The complex bus chassis structure is improved by two stage optimizations. In the first stage optimization, components in the neighbor of few locations with high stresses are selected, and then sensitivities of stress and weight of selected components with respect to component thicknesses are computed. Component thicknesses with high sensitivities ratio of stress to weight are chosen as design variables. Then the structural optimization is performed to reduce the high stress regions with minimum increased weight. In the second stage optimization, thick components not in the neighbor of the locations with high stresses are selected, and then sensitivities of stiffness and weight of selected components with respect to component thicknesses are computed. Component thicknesses with low sensitivities ratio of stiffness to weight are chosen as design variables. Then the structure optimization is performed to reduce the chassis weight while maintaining the improved strength and original stiffness. Finally, static structural characteristics of the original and improved chassis structures are compared, and it shows that the improved chassis is a better structural design

Stable Hydrogen and Oxygen Isotopes for Groundwater Sources of Penghu Islands, Taiwan

This study used stable hydrogen and oxygen isotopes as natural tracers to investigate their isotopic composition in precipitation, and in shallow and deep groundwater in the Penghu Islands in the Taiwan Strait. We aimed to understand the differences and relationships in isotope compositions within various water bodies and to evaluate the source of groundwater recharge. The hydrogen and oxygen isotopic compositions of sampled groundwater are mainly distributed along the meteoric water line in the Penghu Islands, the variations in the distribution range being minor (the δD values are distributed from −48.2‰ to −37.7‰, with a mean value of −43.14 ± 2.4‰; the δ18O values are distributed from −6.96‰ to −5.46‰, with a mean value of −6.34 ± 0.34‰). The data suggest that the groundwater is sourced mainly from local precipitation. In addition, a comparison of the hydrogen and oxygen isotopic compositions of groundwater and precipitation in Taiwan shows that the δ values for groundwater are distributed between those for precipitation during the northeast monsoon and the southwest monsoon seasons. However, some of the δ values trends towards the isotopic composition of the precipitation during the southwest monsoon season. Thus, the source of groundwater may have a closer association with precipitation during this time

以標準化地下水與降雨指數法評估高屏溪流域之乾旱特性

Taiwan has been facing severe water crises in recent years owing to the effects of extreme weather conditions. Changes in precipitation patterns have also made the drought phenomenon increasingly prominent, indirectly affecting groundwater recharge. Hence, in the present study, long-term monitoring data were collected from the study area of the Kaoping River Basin. Specifically, data from six selected groundwater level stations and six precipitation stations in the vicinity were collected between 1997 and 2014. The standardized groundwater index (SGI) and standardized precipitation index (SPI) were then used to analyze the region's drought characteristics. The results revealed continuous droughts occurred in the river basin from 2003 to 2005. The trend for 2014 further indicated the drought situation in the region would worsen in terms of severity. After calculation and analysis of the cross correlation function between the SGI and the SPI, a positive correlation was identified between the maximum cross correlation function (q_(max)) and the duration of the drought event. The larger the q_(max) value, the longer the duration of the drought, and vice versa. The study also found the q_(max) value varied with geographical locations: it was smaller for the various measuring stations located along the Qishan and Laonong rivers, but tended to be larger for stations located beyond the Ailiao River. Thus, this study reckoned if a drought event were to occur in the latter area in the future, its duration would be relatively longer. The findings of this study could also serve as future reference for the water resources management of the Kaoping River Basin.近年來受到極端氣候的影響，臺灣面臨嚴重的缺水危機，且因降雨型態的改變，使得乾旱現象愈趨明顯，間接影響地下水的補注。因此，本研究以高屏溪流域作為研究區域，選定6 個地下水位站及鄰近6 個雨量站之長時間監測資料，利用標準化地下水指數評估法 (Standardised Groundwater Index, SGI) 與標準化雨量指數評估法 (Standardised Precipitation Index, SPI) 分析該區域乾旱特性。本研究分析高屏溪流域1997 年至2014 年地下水位與雨量資料，結果顯示，2003 年至2005 年為高屏溪流域之連續乾旱年，且由2014 年的趨勢判斷高屏溪流域乾旱之嚴重程度有逐漸上升的趨勢。另外，透過計算SGI 和SPI 兩者間的交互相關函數分析其最大交互相關函數 (q_(max))，結果顯示q_(max) 與乾旱事件持續的時間為正相關，並得知q_(max) 越大發生乾旱事件持續的時間越長，反之當q_(max) 越小則持續時間越短。且由研究結果發現q_(max) 具有地理位置上的差異性，位於旗山溪與荖濃溪所處各測站之q_(max) 較小，而位於隘寮溪以下測站之q_(max) 呈現較大之情形，所以未來若隘寮溪以下之區域發生乾旱事件，本研究推估其乾旱的持續時間也會相對較長。本研究結果亦可提供未來高屏溪流域水資源管理參考

UIST 2020 - Proceedings of the 33rd Annual ACM Symposium on User Interface Software and Technology

The automatic recognition of how people use their hands and fingers in natural settings - without instrumenting the fingers - can be useful for many mobile computing applications. To achieve such an interface, we propose a vision-based 3D hand pose estimation framework using a wrist-worn camera. The main challenge is the oblique angle of the wrist-worn camera, which makes the fingers scarcely visible. To address this, a special network that observes deformations on the back of the hand is required. We introduce DorsalNet, a two-stream convolutional neural network to regress finger joint angles from spatio-temporal features of the dorsal hand region (the movement of bones, muscle, and tendons). This work is the first vision-based real-time 3D hand pose estimator using visual features from the dorsal hand region. Our system achieves a mean joint-angle error of 8.81 degree for user-specific models and 9.77 degree for a general model. Further evaluation shows that our system outperforms previous work with an average of 20% higher accuracy in recognizing dynamic gestures, and achieves a 75% accuracy of detecting 11 different grasp types. We also demonstrate 3 applications which employ our system as a control device, an input device, and a grasped object recognizer