林忠義 博士(中央大學天文研究所)
2018/12/18(二)13:00綜合大樓1樓48111B教室演講
摘要：
With almost a century of experience and several decade observations using ground‐based and space telescopes monitoring in a wavelength band from the cm‐wave radio astronomy to x‐ray, we are confident that we were able to use such data effectively for studying the most of physical properties and chemical abundance of cometary nuclei. However, the chemical composition of cometary nuclei could be different from comet to comet. For instance, SPCs (short period comets) have been subjected more times to solar radiation than LPCs (long period comets), and they should show a lower content of volatile material and a more highly processed surface. In addition, the investigation of the chemical composition is indirect because it considers only molecules that are released from the nucleus surface that can be affected by numerous processes, for instance cosmic ray. Therefore, how the molecular composition and abundance of the coma is related to the one inside the nucleus is still an open issue.
In this talk, I will present recent study of comets from the ground-based observations to space mission and show how important to link ROSETTA’s incredible detail results to ground‐based observations. The link and direct comparison between 67P and other comets observed in the same ways from Earth will be discussed. Furthermore, I will discuss the interaction between cometary plasma tail and solar wind using our observing data set.
| 附件: 20181218.pdf
饒駿頌 博士(Astroparticle Physics Theory Group, DESY)
2018/12/11(二)13:00綜合大樓1樓48111B教室演講
摘要：
With important applications to space, astrophysical, and laboratory environments, plasma wave excitation led by the drift energy of streaming particles (streaming instability) is an extensively studied phenomenon in plasma physics. In the Sun-Earth environment, for instance, the electrostatic streaming instability is generally considered to lie in the origin of the observed electrostatic solitary waves and in the core mechanism of type III solar radio bursts. As in astrophysical environments, a non-resonant type electromagnetic streaming instability is also proposed as a candidate for the amplification of interstellar magnetic fields in the upstream region of supernova remnant shocks, which plays an important role in the efficiency of cosmic-ray particle acceleration.
In this talk I will present my past studies of streaming instability problems from linear theory and numerical simulation, to the application to laboratory astrophysics experiments. The research topics include the formation of phase-space electron-hole structure in the electron-positron plasma, fire-hose-type electromagnetic streaming instabilities, and cosmic-rays driven magnetic field amplification. Together with these ongoing projects, I will also discuss potential future approaches within this rich research field.
| 附件: 20181211.pdf
張晃崇 博士(台灣優貝克科技)
<專題討論>2018/12/6(四)14:10綜合大樓2樓48218教室演講
Prof. Satoshi Hamaguchi(Center for Atomic and Molecular Technologies, Graduate School of Engineering, Osaka University, Osaka, Japan)
<專題討論>2018/11/29(四)14:10綜合大樓2樓48218教室演講
摘要：
As the sizes of semiconductor devices continue to diminish and are now approaching atomic scales, the downsizing of transistors following Moore’s law is bound to end in the near future. However, the continuing market demand for higher performance and lower energy consumption of large-scale integrated (LSI) circuits has driven invention of new device technologies such as three-dimensional (3D) device structures and devices based on non-silicon materials. Manufacturing of these non-conventional devices also poses new challenges for processing technologies. One of the latest processing technologies that are considered crucial in modern semiconductor technologies is Atomic-Layer Processes (ALPs), which typically refers to Atomic Layer Deposition (ALD) and Atomic Layer Etching (ALE). In these processes, deposition or etching processes take place layer by layer in atomic sclae. For example, in plasma-based ALE of SiO2 films, deposition of a few-angstrom deep fluorocarbon (FC) layer on a SiO2 film and a subsequent application of low-energy Ar+ ions to the fluorocarbon-deposited SiO2 film causes sub-mono-layer etching of the SiO2 surface. By repeating these steps, a layer-by-layer etching of SiO2 can be achieved selectively over other materials such as Si. Despite their low throughput, ALPs are now widely welcomed in industry as they typically allow highly uniform processes over a large area with atomic-scale accuracy. In this lecture, after a brief introduction of plasma processing in general, basics of ALPs will be discussed and latest research results for experimental and computational studies on ALE processes will be presented.
河森榮一郎 教授(成功大學電漿所)
<專題討論>2018/11/22(四)14:10綜合大樓2樓48218教室演講
摘要：
While entropy is elusive, it is an indispensable physical quantity for identifying direction of evolution of thermodynamic many-body systems, measuring decoherence of quantum systems, evaluating the amount of information loss, and so on. Originally it was introduced in order to describe irreversibility of equilibrium thermodynamic systems. The idea of entropy has been expanded into various fields such as quantum computing, information science, evaluation of networks and so on as well as to nonequilibrium systems. In this talk, we consider entropy of classical wave turbulence systems.
The concept of wave turbulence, that describes nonlinearly interacting waves, covers areas of fluid turbulence, optical turbulence, plasma turbulence, and so on. In the field of wave turbulence, wave action, which represents the number of waves as a function of a quantum number such as frequency or wave number, has been a subject of investigation. I propose a new idea representing wave field entropy, that doesn’t require conventional random-phase approximation (RPA). The idea is application of the concept of the von Neumann entropy to classical wave turbulence systems and it is a natural extension of Gibbs entropy (equivalently Shannon entropy in information science). For that purpose, a concept of a density matrix of classical wave fields is introduced together. I show validity of the classical von Neumann entropy to distinguish turbulent states and coherent state having broad spectrum quantitively. Examples, to which my idea is fit, include supercontinuum, optical turbulence, rogue waves, drift wave turbulence and so on, that are recognized as wave turbulence.
| 附件: 20181122 河森榮一郎教授.pdf
李芳承 博士(國家實驗研究院台灣海洋科技研究中心)
<專題討論>2018/11/15(四)14:10綜合大樓2樓48218教室演講
摘要 ：
1.利用雷射光學量測配合高速攝影技術系統拍攝一系列前進波影像，再利用影像處理技巧進行邊緣偵測，數位化、分析波浪連續自由液面高程。其中從全尺度拍攝中，成功地利用 LabVIEW 發展多斷面影像連結技術與邊緣偵測技術，藉由量測 Y 軸向的放大影像觀察所波浪通過結構物理特徵現象。數位化水面高程資料，再透過Matlab發展二維快速傅立葉轉換(2DFFT) 結合一維 Morlet 小波轉換(1DMWT)方法完整分解波浪訊號技術。
2.發展運算模擬平台，以無網格(SPH)數值模式探討水波槽問題(多相流)。
| 附件: 20181115 李芳承博士.pdf
江致宇 博士候選人(成功大學電漿所)
<專題討論>2018/11/8(四)14:10綜合大樓2樓48218教室演講
摘要：
經過數十年來的探索，太空已不再是人類遙不可及的夢想之地，過去利用衛星觀測所累積的各種科學及工程的數據，不但掀開太空中神祕的面紗，一項項待解的太空科學議題也一一獲得驗證，人類對太空的認識已不再是之前瞎子摸象的時代，新的衛星任務目標都更加具體，然而接下來可能會有人想問，什麼是太空探索的下一步呢? 大家或許有注意到，這幾年全球掀起了太空熱，各種創新衛星、載具研發或甚至加值服務都不斷出籠，這一切的推手都可歸功於太空產業走向商業化的成果，而有了這樣好的立基點之後，加快了衛星研發的時程和發射升空的頻率，同時數據資料的累積也預期將以驚人的速度成長。因此，面對太空大數據時代的來臨，我們做好準備了嗎? 從過去到現在所留下的龐大數據資料，是否能進行更有效率的大數據應用與開發，為未來太空AI時代打下基礎呢? 本演講將以太空科學資料(電漿相關)的角度切入，進行介紹與分析，希望聽眾能對太空資料處理流程能有更進一步的認識。
|| 附件: 20181108 江致宇博士候選人.pdf
詹寶珠 特聘教授(成功大學電機系)
<專題討論>2018/11/1(四)14:10綜合大樓2樓48218教室演講
摘要：
Deep learning neural networks have been the main focus in recent researches and applications. In this talk, we will give an introduction of the concept of neural networks and the deep learning models. A brief overview of the development of deep learning network models for image analysis and other applications will be provided. Some mechanisms in achieving successful training will also be discussed.
| 附件: 20181101 詹寶珠特聘教授.pdf
Prof. Golubkov Gennady Valentinovich(Supervisor of the scientific subject “Chemical physics of Earth atmosphere” in the Semenov Institute of Chemical Physics of RAS (Moscow, Russia))
<專題討論>2018/10/25(四)14:10綜合大樓2樓48218教室演講
摘要：
Uncontrollable sporadic distortions of satellite signals of global positioning system (GPS) caused by a phase failure and group-delays in a propagation of electromagnetic radiation through a medium take place in periods of high solar activity and geomagnetic disturbances formation in the Earth's ionosphere. Searching of ways ensuring a sustainability of the GPS system is a fundamental scientific and technical problem. Additional background incoherent ultra-high frequency (UHF) radiation is formed at the altitudes of E and D layers of the Earth ionosphere during these periods. Wavelengths of this radiation correspond to a range from a decimeter to a millimeter. This emission is due to transitions between Rydberg states of atoms and molecules which are excited by electrons in plasma, and are surrounded by a neutral particle environment. Reliable information about of UHF radiation flux power in this wavelength range is not currently available. The answer to this question depends entirely on knowledge of impact and radiation quenching of Rydberg states dynamics and the kinetics of their location in a lower ionosphere, i.e. on the quantum optical properties of a perturbed environment. Analysis of existing experimental data has shown that the UHF radiation is formed in the atmospheric layer located at altitudes of 80-110 km. A physical mechanism of the satellite signal delay is due to cascade resonant scattering of GPS signal photons in the decimeter range while passing through this layer over a set of Rydberg states. The most promising approach to studies of the medium optical quantum properties can be a simultaneous analysis of the background additional noise and the GPS signal propagation time delay which determines a positioning error. Using standard methods of noise measurement one cannot detect physical and chemical processes which are responsible for noise formation and errors affecting the positioning Therefore, the problem can be solved if the level of a background noise will be considered as a noise of the measured GPS signal, since propagation delays of the latter are due to one of the most important atmospheric collisional process, i.e. the orbital degeneracy of highly excited states. For this purpose, it is advisable to use the signal-to-noise ratio, where the signal corresponds to a level of a signal obtained by GPS receiver, and a noise corresponds to GPS signal fluctuations.
In this lection a theory current state is examined and ways of its further development are discussed. They are associated with the progress of theoretical methods for describing of the medium neutral particles impact effects on the dynamics of collision and radiation quenching focusing primarily on elementary processes involving molecules of nitrogen and oxygen. It is shown that preliminary calculations of non-adiabatic transitions dynamics between potential energy surfaces (PES) of Rydberg complexes, the construction of appropriate electronic wave functions, calculations of allowed transition dipole moments and also determination of emission line shapes are necessary for quantitative estimations of excited particles influence on a spectrum of incoherent UHF radiation of the atmosphere. These results should be included in the total kinetic scheme, which establishes dependence of UHF radiation on temperature and density of the lower ionosphere. Then the satellite monitoring data of infrared (IR) radiation, accompanying the UHF radiation, can be directly used for detection of Rydberg states and diagnostics of the plasma parameters.
The lecture is based on the materials of the review
Golubkov G.V., Golubkov M.G., Manzhelii M.I., Karpov I.V. Optical quantum properties of GPS signal propagation medium – D layer. In: The Atmosphere and Ionosphere: Elementary Processes, Monitoring, and Ball Lighting. Eds. Bychkov V.L., Golubkov G.V., Nikitin A.I. New York: Springer, 2014. P. 1-67.
談永頤 教授(成功大學電漿所)
<專題討論>2018/10/18(四)14:10綜合大樓2樓48218教室演講
摘要：
The Energization and Radiation in Geospace (ERG) satellite (nicknamed "Arase"), launched from the Uchinoura Space Center in December 2016, began its regular observations of the inner magnetosphere in March 2017. Among the various instruments aboard the Japanese satellite is the Low‐Energy Particle Experiments ‐ Electron Analyzer (LEP-e), developed by a Taiwanese team that featured members from Academia Sinica and National Cheng Kung University. The instrument measures electrons in the energy range between ~20 eV and 19 keV. As ERG's orbit covers the range of McIlwain L-parameter roughly from 2 to 9, overlapping with that of the auroral oval in the ionosphere, LEP-e is suitable for studying the magnetospheric origins of auroral electrons. In this study, we statistically compare the Auroral Electrojet (AE) index with LEP-e measurements as well as ERG data from the Medium-Energy Particle Experiments - Electron Analyzer (MEP-e). The correlation coefficients between the AE index and measurements at various electron energies enable us to identify the magnetic local times (MLT) together with L for the magnetospheric locations that are most often in association with occurrences of aurora. These parameters, MLT and L, are compared with those at ionospheric locations where auroral electron precipitation is statistically the dominant density-perturbation effect during disturbed times according to observations from another international collaborative satellite mission involving Taiwan, namely FORMOSAT-3/COSMIC.
| 附件: 20181018 談永頤教授.pdf