Finite element beam analysis of tapered thin-walled box beams

Shin, Dongil,Choi, Soomin,Jang, Gang-Won,Kim, Yoon Young Elsevier 2016 Thin-Walled Structures Vol.102 No.-

<P><B>Abstract</B></P> <P>This paper presents a one-dimensional finite element analysis of tapered thin-walled box beams under out-of-plane loads and twisting moments by developing new <SUP> C 0 </SUP> -continuous tapered higher-order beam elements. While higher-order sectional deformations such as distortion were considered earlier, there was no theoretical or finite element analysis on the tapering effect of variable cross-sectioned box beams. Case studies considering tapered box beams with various height-to-width ratios and a system of joint structure with a tapered box beam show that the results by the developed method are comparable with the shell finite element results unlike the stepped Timoshenko beam element results.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Tapered box beams under out-of-plane loads and twisting moments are analyzed. </LI> <LI> One-dimensional tapered higher-order finite beam elements are newly developed. </LI> <LI> The tapering effect is considered with sectional warping and distortion reflected. </LI> <LI> Beams with various height-to-width ratios and a problem having a joint were tested. </LI> </UL> </P>

Higher-order beam theory for static and vibration analysis of composite thin-walled box beam

Shin, Dongil,Choi, Soomin,Jang, Gang-Won,Kim, Yoon Young Elsevier 2018 COMPOSITE STRUCTURES -BARKING THEN OXFORD- Vol.206 No.-

<P><B>Abstract</B></P> <P>A higher-order beam theory suitable for accurate analysis of composite thin-walled box beams is developed. Because anisotropic and laminate effects in composite beams produce deformation patterns that do not appear in isotropic beams, accurate analyses for composite beams require elaborately defined sectional shape functions that describe local cross-sectional deformations. Here, we present a new systematic method to define these functions and establish a one-dimensional finite element based on a higher-order beam theory for composite thin-walled box beams. The validity of the developed approach is checked by solving static and eigenvalue problems with composite thin-walled box beams, and by comparing the obtained numerical results with those obtained by ABAQUS shell elements.</P>

Multiple linear regression and GRU model for the online prediction of catalyst activity and lifetime in counter-current continuous catalytic reforming

Shin Yongbeom,박명남,Lee Jaewook,Kang Kibyung,Wang Sungki,Lee Eunsung,Song Seongkeun,Shin Dongil 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.6

In the catalytic reforming process, aromatic yield is a standard for evaluating the production quality of the process, and studies are underway to improve productivity by optimizing the cost and energy. In particular, the activity and lifetime prediction of reforming catalysts can contribute to overall process efficiency improvement, such as product quality, productivity, and predictive maintenance. However, it is difficult to predict real-time catalyst activity and lifetime according to changes in process operation with the existing method that requires experimental data. In this study, a multiple linear regression (MLR) model and GRU model with the real process operating data are proposed for long-term plant operation and optimization in the counter-current continuous catalytic reforming. The MLR-GRU model predicts catalyst performance degradation and lifetime according to operating conditions by defining a new variable, reforming catalyst activity. The proposed model can predict the future reformate yield with an error of less than 1%. As a result of predicting the catalyst lifetime according to various operating temperatures, feed flow patterns, and feed quality, the feed flow rate had the greatest influence on the catalyst lifetime profile. In terms of the amount of produced reformate oil, the case with maximum feed rate is the worst (−25.6%); on the other hand, the case with minimum feed rate is the best (+11.4%). Thus, it is important to establish an appropriate production plan of the produced reformate oil. The model proposed in this study can predict the reformate yield and lifetime, reflecting the degradation of catalyst performance according to the operating profile in real-time, which is expected to improve productivity by production scheduling, optimization, and predictive maintenance.

Quantified Design Guidelines of a Compact Transformerless Active EMI Filter for Performance, Stability, and High Voltage Immunity

Shin, Dongil,Jeong, Sangyeong,Kim, Jingook IEEE 2018 IEEE TRANSACTIONS ON POWER ELECTRONICS - Vol.33 No.8

<P>This paper proposes and analyzes a compact transformerless common mode active electromagnetic interference (EMI) filter (AEF) using a push–pull amplifier. Quantified design guidelines are then rigorously derived from the analysis with consideration for performance, stability, and high voltage transient immunity. The proposed AEF is manufactured based on the design guidelines, and its performance is validated by measurements using a vector network analyzer. The AEF is then implemented into a real 2.2 kW current resonant inverter, and the conducted emissions are reduced by 5–25 dB at a frequency range from 150 kHz to 6 MHz. In addition, the AEF's immunity against high voltage transients is demonstrated by lightning surge tests.</P>

영어과 평가에서 다차원구조와 모형에 관한 논의

Dongil Shin 한국응용언어학회 2000 응용 언어학 Vol.16 No.1

Incremental learning method for cyber intelligence, surveillance, and reconnaissance in closed military network using converged IT techniques

Shin, Gyeongil,Yooun, Hosang,Shin, Dongil,Shin, DongKyoo Springer-Verlag 2018 Soft computing Vol.22 No.20

RECENT ADVANCES OF BIOTECHNOLOGY IN FOREST TREE IMOPROVEMENT

SHIN,Dongill 대구효성가톨릭대학교 1997 연구논문집 Vol.55 No.2

임목은 다른 초본류와 달리 오랜 영양생장기간, 큰 부피 및 그에 따른 넓은 공간의 필요성등의 이유로 육종에 많은 어려움이 있다. 이러한 장애는 생명공학적 방법을 이용하여 상당부분 해소할 수 있으며 방법들로는 조직배양을 통한 대량 증식 및 체세포 배양, 유전자 mapping을 통한 유용 유전자 발굴과 조기 선발, 유용유전자의 도입을 통한 형질전환법 등이 있다. 조직배양을 이용한 대량증식은 뉴질랜드에서 이미 상업적으로 이용되고 있으며 국내에서도 그 가능성이 검증된 바 있다. 형질전환에 의한 유용 유전자 도입은 제초제 내성, 해충 내성, 스트레스 내성, 리그닌 합성저해 유전자 등이 임목에 도입되어 현재 형질전환체가 만들어 졌으며 이들에 대한 분석이 진행되고 있다. 임목에 대한 생명공학의 응용은 많은 기대와 가능성을 인정 받고 있으나 실용화를 위해서는 임목에 대한 분자 유전학적 정보에 대한 보다 많은 연구가 필요할 것이다.

An Integrated Diagnostic System Based on the Cooperative Problem Solving of Multi-Agents: Design and Implementation

Shin Dongil,Oh Taehoon,Yoon En Sup The Korean Institute of GAS 2004 한국가스학회지 Vol.8 No.2

Enhanced methodologies for process diagnosis and abnormal situation management have been developed for the last two decades. However, there is no single method that always shows better performance over all kinds of diagnostic problems. In this paper, a framework of message-passing, cooperative, intelligent diagnostic agents is presented for improved on-line fault diagnosis through cooperative problem solving of different expertise. A group of diagnostic agents in charge of different process functional perform local diagnoses in parallel; exchange related information with other diagnostic agents; and cooperatively solve the global diagnostic problem of the whole process plant or business units just like human experts would do. For their better understanding, sharing and exchanging of process knowledge and information, we also suggest a way of remodeling processes and protocols, taking into account semantic abstracts of process information and data. The benefits of the suggested multi-agents-based approach are demonstrated by the implementations for solving the diagnostic problems of various chemical processes.

Korean EFL Learners’ Acquisition of Voiceless Interdental Fricative

Dongil Shin,Gina Kang 현대문법학회 2011 현대문법연구 Vol.65 No.-

The purpose of this study is to investigate the production of English interdental fricative [θ] by Korean EFL learners. This study also examines participants’ tendency to substitute [θ] with four possible variants. Data is gathered from 17 EFL learners who are asked to demonstrate four oral production tasks. The speech styles are collected by interview, reading aloud a passage, a word list with minimal pairs, and a picture story telling. In addition, participants are asked to fill their preferred variants for (th) on the questionnaire given. After using the Praat program to analyze data, the study shows that phonological variation in English (th) is systematically affected by (1) internal factors (phono- logical factors): following front vowel and syllable positions; (2) external factor: speech style. With regard to phonological factors, high frequency plays a crucial role and high frequency words are more quickly to go through the progress of the acquisition of (th)-sound. As for the effect of external context, word-list reading and passage reading strongly promotes accurate (th), while story telling inhibits it. The study also suggests that the more attention is paid to speech, the more accurate production will be produced. Finally, the language attitude questionnaire revealed that /s/ is not only the acceptable substitute but also the students’ preferred variant for (th)-sound.

Quantified Design Guides for the Reduction of Radiated Emissions in Package-Level Power Distribution Networks

Dongil Shin,Namsu Kim,Jongjoo Lee,Youngwoo Park,Jingook Kim [Institute of Electrical and Electronics Engineers 2017 IEEE transactions on electromagnetic compatibility Vol.59 No.2

<P>Closed-form expressions of radiated emissions from power distribution networks (PDNs) in packages are derived based on the equivalent lumped-circuitmodel. The expressions are validated with results from full-wave numerical computations and far-field measurements. The effects of the small planar PDN structures on radiated emissions are quantitatively investigated based on the sensitivity analysis. Using the closed-form expressions, a systematic procedure for developing quantified PDN design guidelines to suppress the radiated emissions is formulated, which is then demonstrated with a test prototype PDN. The method allows the electromagnetic compatibility aware PDN design in the initial design stage.</P>