Asymmetric Structures of a Squall-Line MCS over Taiwan with Significant Hydraulic Jumps

Yu‑Tai Pan,Ming‑Jen Yang 한국기상학회 2022 Asia-Pacific Journal of Atmospheric Sciences Vol.58 No.3

On 19 April 2019, a mature squall-line mesoscale convective system (MCS) with the characteristics of a leading convective line and trailing stratiform landed on Taiwan, resulting in strong gust wind and heavy rainfall. This squall-line MCS became asymmetric after landfall on Taiwan. Two sets of idealized numerical simulations (mountain heights and low-level vertical wind shear) using the Weather Research and Forecasting (WRF) model were conducted to examine the impacts of realistic Taiwan topography on a squall-line MCS. Results showed numerous similarities between the idealized simulations and real-case observations. The low-level Froude number which considered the terrain height ( Fmt) was calculated to examine the blocking effect of the Taiwan terrain, and the cold pool (determined by − 1.5 K isotherm) was found to be completely blocked by the 500-m height contour. The northeast-southwest orientation of the Snow Mountain Range (SMR), and the north–south orientation of the Central Mountain Range (CMR) led to the upwind side asymmetry. On the other hand, the lee-side asymmetry was associated with different intensities and occurrence locations of the hydraulic jump between the SMR and southern CMR, and the cold-pool Froude number ( Fcp) indicated the flow-regime transition from subcritical to supercritical.

충남대학교 공업기술 계열 교사 연수 프로그램에 대한 만족도 분석

류창열,최유현,김판욱,김기수,김태훈,이창훈 忠南大學校 工業敎育硏究所 2005 論文集 Vol.27 No.1

The purpose of this study was to analyze the educated teachers' satisfaction of the in-service education programs of industrial technical and technology teachers in Chungnam National University. This study was carried out through survey to accomplish the purpose. The number of questionnaires collected was 86. This study used the SPSS program to conduct a descriptive analysis of the data. The results of this study were as follows: (1) The satisfaction about 'teachers' participation', 'utilization of audiovisual materials and instruments' and 'level of professor and lecture' was relatively high. (2) The satisfaction about 'environments of in-service education programs', 'evaluation of achievement', and 'efficacy of lectures' was relatively low.

난소절제 고혈압 백서에서 에스트로겐 투여가 혈관반응성에 미치는 영향

서봉관,최동주,황진용,천일석,이유판 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.4

A Comprehensive Review of Emerging Computational Methods for Gene Identification

Yu, Ning,Yu, Zeng,Li, Bing,Gu, Feng,Pan, Yi Korea Information Processing Society 2016 Journal of information processing systems Vol.12 No.1

Gene identification is at the center of genomic studies. Although the first phase of the Encyclopedia of DNA Elements (ENCODE) project has been claimed to be complete, the annotation of the functional elements is far from being so. Computational methods in gene identification continue to play important roles in this area and other relevant issues. So far, a lot of work has been performed on this area, and a plethora of computational methods and avenues have been developed. Many review papers have summarized these methods and other related work. However, most of them focus on the methodologies from a particular aspect or perspective. Different from these existing bodies of research, this paper aims to comprehensively summarize the mainstream computational methods in gene identification and tries to provide a short but concise technical reference for future studies. Moreover, this review sheds light on the emerging trends and cutting-edge techniques that are believed to be capable of leading the research on this field in the future.

DEVELOPMENT OF CHINA LIGHT-DUTY VEHICLE TEST CYCLE

Yu Liu,Zhi Xin Wu,Hua Zhou,Han Zheng Nan Yu,Xiao Pan An,Jing Yuan Li,Meng Liang Li 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.5

Driving cycles provide a basis for vehicle development and calibration and also serves as the foundation for energy consumption and emissions certification of vehicles. This paper presents the China Light-Duty Vehicle Test Cycle (CLTC) developed by the China Automotive Technology & Research Center (CATARC). First, the important steps and technical routes toward the CLTC development process are summarized. Second, the specific CLTC development process is presented in detail, including the data acquisition and data analysis procedures, weighting factor development and driving cycle construction. Then, the main driving characteristics of the New European Driving Cycle (NEDC), the Worldwide Harmonized Light-Duty Vehicles Test Cycle (WLTC), the Federal Test Procedure (FTP-75), the CLTC and the actual collected data are compared. The CLTC has low average speed, a high idle speed ratio and more frequent acceleration and deceleration characteristics. Finally, 70 vehicles are t ested based on the NEDC, WLTC, and CLTC according to their legislative procedures in the vehicle emission laboratories of the CATARC and the manufacturers. The results show that the CLTC’s fuel consumption is much higher than that of the NEDC and WLTC, and CLTC can effectively reflect the actual fuel consumption of users.

Deep Learning in Genomic and Medical Image Data Analysis: Challenges and Approaches

Yu, Ning,Yu, Zeng,Gu, Feng,Li, Tianrui,Tian, Xinmin,Pan, Yi Korea Information Processing Society 2017 Journal of information processing systems Vol.13 No.2

Artificial intelligence, especially deep learning technology, is penetrating the majority of research areas, including the field of bioinformatics. However, deep learning has some limitations, such as the complexity of parameter tuning, architecture design, and so forth. In this study, we analyze these issues and challenges in regards to its applications in bioinformatics, particularly genomic analysis and medical image analytics, and give the corresponding approaches and solutions. Although these solutions are mostly rule of thumb, they can effectively handle the issues connected to training learning machines. As such, we explore the tendency of deep learning technology by examining several directions, such as automation, scalability, individuality, mobility, integration, and intelligence warehousing.

Numerical simulation of unsteady propeller force for a submarine in straight ahead sailing and steady diving maneuver

Pan, Yu-cun,Zhang, Huai-xin,Zhou, Qi-dou The Society of Naval Architects of Korea 2019 International Journal of Naval Architecture and Oc Vol.11 No.2

In order to provide a complementary perspective to the effects of the maneuvering motions on the unsteady propeller performance, the numerical simulation of the flow field of the hull-rudder- propeller system is performed by Unsteady Reynolds-averaged Naiver-Stokes (URANS) method. Firstly, the flow fields around the submarine model without the presence of propeller in straight ahead motion and the steady diving maneuvers with submergence rudder deflections of 4°, 8° and 12° are predicted numerically. The non-uniformity characteristic of the nominal wake field is exacerbated with the increase submergence rudder angle. Then the flow field around the SUBOFF-G submarine fitted with the 4381 propeller is simulated. The axial, transverse and vertical unsteady propeller forces in different maneuvering conditions are compared. In general, as the submarine maneuvers more violently, the harmonic amplitudes of the unsteady force at the 2BPF and 3BPF increased more significantly than that at BPF.

Effect of scramjet combustor configuration on the distribution of transverse injection kerosene

Pan Yu,Dai Junfei,Bao Heng 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.12

The effect of combustor configuration on the distribution of transverse injection kerosene was investigated in a direct-connected supersoniccombustor equipped with multi-cavities, at the inflow condition of Ma = 2.64. The combustor configuration included a single cavity,cavities in tandem and cavities in parallel. The distribution of kerosene injected upstream of a cavity was observed by high speedphotography. The experiments showed that the kerosene transverse jet shows strong turbulence characteristics. Only a small portion ofkerosene can be engulfed into the cavity, as the main portion is transported downstream in the core flow. Even with a high injection pressure,the kerosene jet from one side of the combustor cannot achieve a well distribution, since the kerosene cannot cross through the mainflow to reach the opposite side wall. Double cavities in tandem show a better performance in improving mixing and penetration for kerosenein the core flow, and the sequence of cavities seems have no effect on the injection. By increasing the fuel injection pressure, morekerosene is injected into the core flow, and less is engulfed into the cavity.

Eu³⁺→Eu²⁺ unusual reduction and bond energy in MAlSi₂O₆:Eu (M = Li, Na, K, Rb, Cs)

Pan, Yu,Wang, Wenjun,Zhu, Yuhan,Xu, Haibing,Noh, Hyeon Mi,Jeong, Jung Hyun,Liu, Xiaoguang,Li, Ling Elsevier 2018 CERAMICS INTERNATIONAL Vol.44 No.7

<P><B>Abstract</B></P> <P>Eu-doped MAlSi<SUB>2</SUB>O<SUB>6</SUB> (M = Li, Na, K, Rb, Cs) phosphors were synthesized by solid-state reaction in air. The crystal structure and optical properties of the phosphors were investigated by X-ray powder diffraction and photoluminescence. Their emission spectra are composed of some broad bands coming from the 5d-4f transition of Eu<SUP>2+</SUP> and some sharp emission peaks coming from the f-f transitions of Eu<SUP>3+</SUP>. The co-existence of Eu<SUP>3+</SUP> and Eu<SUP>2+</SUP> cations is detected in MAlSi<SUB>2</SUB>O<SUB>6</SUB>:2%Eu, which shows that the unusual Eu<SUP>3+</SUP>→Eu<SUP>2+</SUP> reduction process occurs in MAlSi<SUB>2</SUB>O<SUB>6</SUB>. The preferential occupancy of Eu<SUP>3+</SUP> or Eu<SUP>2+</SUP> in MAlSi<SUB>2</SUB>O<SUB>6</SUB> can be calculated to be M<SUP>+</SUP> sites by the bond-energy method. The deviation of the Eu<SUP>3+</SUP>–O<SUP>2-</SUP> bond energy is closed to that of the Eu<SUP>2+</SUP>–O<SUP>2-</SUP> bond energy, which means that Eu<SUP>3+</SUP> and Eu<SUP>2+</SUP> can coexist in air. The abnormal reduction of Eu<SUP>3+</SUP> to Eu<SUP>2+</SUP> can be explained by charge compensation model. The doped Eu<SUP>3+</SUP> was induced to M<SUP>+</SUP> and the vacancy (<I>V</I> <SUB> <I>M</I> </SUB>) may be formed. The vacancy(<I>V</I> <SUB> <I>M</I> </SUB>) acted as a donor of electrons, and the Eu M ∙ ∙ defect acted as an acceptor of electrons. The theoretical result is consistent with the experimental phenomenon.</P>

Numerical simulation of unsteady propeller force for a submarine in straight ahead sailing and steady diving maneuver

Yu-cun Pan,Huai-xin Zhang,Qi-dou Zhou 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.2

In order to provide a complementary perspective to the effects of the maneuvering motions on the unsteady propeller performance, the numerical simulation of the flow field of the hull-rudder- propeller system is performed by Unsteady Reynolds-averaged Naiver-Stokes (URANS) method. Firstly, the flow fields around the submarine model without the presence of propeller in straight ahead motion and the steady diving maneuvers with submergence rudder deflections of 4, 8 and 12 are predicted numerically. The non-uniformity characteristic of the nominal wake field is exacerbated with the increase of submergence rudder angle. Then the flow field around the SUBOFF-G submarine fitted with the 4381 propeller is simulated. The axial, transverse and vertical unsteady propeller forces in different maneuvering conditions are compared. In general, as the submarine maneuvers more violently, the harmonic amplitudes of the unsteady force at the 2BPF and 3BPF increased more significantly than that at BPF.