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アイスジャム発生過程を踏まえた発生箇所・時期の予測手法の検討
Get PDF結氷河川の解氷期に発生するアイスジャムは，水位の急上昇や流下河氷への巻き込まれ事故などを引き起こすこともあり，結氷河川の維持管理上の課題の１つとなっている．アイスジャムによる被害軽減策として，アイスジャムの発生場所・時期の予測技術の開発を進めているが，実務利用の観点から，これら個別の予測手法の特徴を踏まえ，どの時期・手順・条件により各手法での検討を行うのがふさわしいか検討が必要である．発生までの河氷の解氷開始から流下・破壊・堆積までの一連過程を考慮した検討手順を整理し，その適用性を検討した．特に①各河道におけるアイスジャム発生可能性の高い箇所の適切な事前抽出，②解氷の開始時期の適切な事前予測，③アイスジャム発生危険度が高まる時期の適切な事前予測の観点から，適切な予測が可能かどうかを検討した．journal articl
Analysis of NRD guide devices using rigorous two-dimensional full-vectorial FDTD method
Get PDFIn this paper, a rigorous two-dimensional full-vectorial finite difference time domain (2D-FVFDTD) method is developed for an efficient analysis of nonradiative dielectric waveguide (NRD guide) devices with three-dimensional structure. A Convolutional perfectly matched layer is employed as an absorbing boundary condition. Furthermore, we have established a rigorous formulation for estimating the modal power of each and mode. We confirmed the validity of the proposed method through the analysis of NRD crossing and T-branch guide devices. Excellent accuracy is achieved by the cross comparison of 2D-FVFDTD results with recently developed two-dimensional full vectorial finite element method.journal articl
Annual Report of Open Facility Center Kitami Institute of Technology Vol.20
Get PDF◆巻頭 共用設備センター長 阿部 良夫
◆研究紹介
「波長分散型蛍光X線分析法による土壌中可給態肥料成分の迅速分析」
地球環境工学科 宇都 正幸 …1
◆共同利用機器の紹介
「紫外可視近赤外分光光度計」
技術部 橋本 晴美…5
◆利用実績…6
◆設置機器類…35
◆活動報告…36
◆編集後記…38othe
4α linear-chain state produced by 9Be + 9Be collisions
Get PDFThe linear-chain (LC) structure provides significant insights into quantum many-body systems with geometric configurations. In this study, 4α + 2n LC was assessed in 18O. The excitation energies, moment of inertia,and α- and 9Be-decay widths of the LC states were predicted using antisymmetrized molecular dynamics. We predict that there are two 4α LC bands, Kπ = 0+ and Kπ = 3?, which exhibit different decay properties. We demonstrate that the Kπ = 3? LC states can be verified by the head-on 9Be+9Be collision experiments because their states exhibited large decay widths in the 9Be+9Be channel.journal articl
Heavy snowfall and snow damage in the Sapporo metropolitan area during 2021-22 winter (Part 2) - Comparison of snow profile observations between the Sapporo metropolitan area and the central, eastern, and northern Hokkaido regions -
Get PDFThis report summarizes snow profile observations by the JSSI Hokkaido Branch Snow Damage Research Team in the
Sapporo metropolitan area during the winter of 2021–2022. The snowpack of this winter had thick layers of compressed
snow or granular snow formed during heavy snowfall. There were few or no ice layers within the snowpack. Owing to
the accumulation of wet snow from December to January, a high-density layer was present in the lower layer. Furthermore,
the snowpack characteristics observed in the Sapporo metropolitan area were compared with the observation results in
central, eastern, and northern Hokkaido during the same period.journal articl
オホーツク地域における大雪時の積雪特性とその要因 -2014/15 年冬期の事例解析-
Get PDFThis study analyzed the increase in maximum daily snow depth, main snow types, and background meteorological
conditions during a heavy snow season (winter 2014/15) in the Okhotsk region of Hokkaido. Consequently, the maximum
daily snow depth substantially increased under the influence of a rapidly developing extratropical cyclone. During the
heavy snow season, temperature gradients within the snowpack were small because temperatures remained above normal,
and the snow types were primarily compacted snow and granular snow. These findings are important in the Okhotsk
region, where snow pit observation data are limited.journal articl
Improving Multilingual Automatic Cyberbullying Detection With Feature Density And Cross-lingual Zero-shot Transfer
Get PDF北見工業大学博士（工学）In this thesis, I study two different methods for improving multilingual automatic cyberbullying
detection. First, I study the effectiveness of Feature Density (FD) using different linguisticallybacked
feature preprocessing methods in order to estimate dataset complexity, which in turn is
used to comparatively estimate the potential performance of machine learning (ML) classifiers
prior to any training. I hypothesize that estimating dataset complexity allows for the reduction
of the number of required experiments iterations, making it possible to optimize the resourceintensive
training of ML models which is becoming a serious issue due to the increases in available
dataset sizes and the ever rising popularity of models based on Deep Neural Networks (DNN).
The problem of constantly increasing needs for more powerful computational resources is also
affecting the environment due to alarmingly-growing amount of CO2 emissions caused by training
of large-scale ML models. I use cyberbullying datasets collected for multiple languages, namely
English, Japanese and Polish. The difference in linguistic complexity of datasets allows me to
additionally discuss the efficacy of linguistically-backed word preprocessing.
Second, I study the selection of transfer languages for automatic abusive language detection.
I demonstrate the effectiveness of cross-lingual transfer learning for zero-shot abusive language
detection. This way it is possible to use existing data from higher-resource languages to build
better detection systems for languages lacking data. The datasets are from eight different languages
from three language families. I measure the distance between the languages using several language
similarity measures, especially by quantifying the World Atlas of Language Structures. I show
that there is a correlation between linguistic similarity and classifier performance, making it
possible to choose an optimal transfer language for zero shot abusive language detection.
Next, I demonstrate that this method is also generally applicable to multiple Natural Language
Processing tasks, specifically sentiment analysis, named entity recognition and dependency parsing.
I show that there is also a correlation between linguistic similarity and zero-shot cross-lingual
transfer performance for these tasks, allowing me to select an ideal transfer language in order to
aid with the problem of dealing with languages that do not currently have a sufficient amount
of data. Lastly, I show that the World Atlas of Language Structures can be quantified into an
effective linguistic similarity method.doctoral thesi