전역 최적화 기법을 활용한 강재 댐퍼의 최적 설계 및 성능 검증

차영욱 ( Cha¸ Young-wook ),백창현 ( Baek¸ Chang-hyun ),허종완 ( Hu¸ Jong-wan ) 한국복합신소재구조학회 2021 복합신소재구조학회논문집 Vol.12 No.5

현재 국내외적으로 다양한 강재 댐퍼의 형상에 대한 연구가 이뤄지고 있다. 강재 댐퍼는 제진장치 중 하나로 항복을 통해 지진에너지를 흡수 및 소산하여 본 구조물을 보호한다. 최근 적용되고 있는 면내 전단 변형에 의해 작동하는 댐퍼는 응력이 특정 부위에 집중되어 재료의 대부분이 본래의 역량을 발휘하지 못하는 한계가 있었다. 따라서, 본 연구에서는 이 한계를 극복하고자 전역 최적화 기법 중 하나인 뻐꾸기 탐색을 적용해 최적 형상을 설계하였다. 탐색된 최적 형상을 토대로 수치해석과 실제 실험을 통한 성능검증을 수행했다. 최적 형상으로 설계된 댐퍼는 안정적인 이력거동을 보이고, 높은 에너지 소산능력을 확보하는 것으로 나타났다. 본 연구에서는 전역 최적화 기법을 적용한 최적 설계 방법을 제시하고 그 결과를 검증함으로써, 다양한 형태의 공학적 문제 해결에 대한 적용 가능성을 제시하였다. Studies on the shape of various steel dampers are currently being conducted globally. The steel damper is a vibration-damping device that protects a structure by absorbing and dissipating seismic energy via yielding. Recent steel dampers operated by in-plane shear deformation have a drawback; most of the materials used in steel dampers do not work to their full capacity due to the concentration of stress in a specific area. Therefore, to overcome this limitation, the optimal shape of the damper used in this study was designed by applying the cuckoo search, which is a global optimization technique. The performance of the optimized shape was verified using numerical analysis and actual experiments. The damper showed stable hysteresis behavior and high-energy dissipation capacity, thereby suggesting its application to various types of engineering problem solutions.

조선일보사 『소년(少年)』지(誌)의 편집체계와 독자 연구

류영욱 ( Ryu¸ Young-wook ) 문창어문학회 2020 문창어문논집 Vol.57 No.-

The purpose of this book is to examine the form of readership at that time, focusing on the editing system of 『Sonyoen』 published by the Chosun Ilbo in the 1930s. Although it was a children's magazine that was founded in April 1937 and closed in December 1940, 『Sonyoen』 has not been noted for research in the past years, even though it was a major children's periodical that existed in the late 1930s. This paper was intended to examine the media characteristics and aspects of independent differentiation of 『Sonyoen』, 『Children』, 『Sinsonyoen』 as a method of positivism. First, we looked at the discovery of 『Sonyoen』 and the creation of children's magazines in the beginning of modern children's literature. In addition, the meaning of 『Sonyoen』 the subject of this study, was determined by comparing it with 『Sonyoen』 led by Choi Nam-sun in 1908. 『Sonyoen』 advocated a multi-child magazine and showed a ground for commerciality and popularity. The pages, consisting of epic literature, poetry literature, culture, and other publications, were carried out under the independent plan of entertainment and culture. The pages of the Japanese propaganda campaign were also set up, which is suspected of internalizing the ideology of war and Japanese rule. But this can be understood in terms of a compromise for the survival of the magazine. In this way, 『Sonyoen』 kept his value as a magazine published in Korean as a venue for the presentation of one of the few works of the time for readers and writers. Readers have become active readers in magazines through the readership system. The ‘Sonyoen Storyroom’ was a multi-layered communication channel, and the ‘a literary section’ served as a stage for readers' independent growth. The readers have made a new change by actively utilizing these systems. It has emerged from the deep-rooted hierarchy of children's literature and has a status as a consumer who recognizes and enjoys magazines as a cultural products. In addition, voluntary and active readership changes are accelerating due to the formation of independent critical communities.

『단경(壇經)』의 북종비판(北宗批判)

金榮郁 ( Kim¸ Young Wook ) 성철사상연구원 1994 백련불교논집 Vol.4 No.-

The relationship between low blood lead level(<10 μg/dL), blood pressure and Hypertension in South Korean male lead exposed workers

Youngwook Kim,Juha Park,Jihyun Shin,Yongduk Ahn,Jeongbae Rhie,Mingi Kim,Sangchul Roh,Yeon-Soon Ahn 대한직업환경의학회 2019 대한직업환경의학회 학술대회 논문집 Vol.2019 No.5

Value Creation in Industry Digital Convergence

Youngwook Kim,Youngho Lee,Youngjin Kim,Yuhwan Kim 대한산업공학회 2007 대한산업공학회 춘계학술대회논문집 Vol.2007 No.5

Development of Rice-paper Manufacturing Machine and Evaluation Rice-paper Physical Property

( Youngwook Seo ),( Jong-ryul Park ),( Hoeman Park ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.2

In order to resolve the redundant rice issue, development of rice processing machinery is an alternative solution. We developed the rice-paper manufacturing machine for performance test and finding optimal recipe rice-paper producing. Capacity of a machine is 30kg/h, input power is 220V, and consuming electric power is 3kW. The size of machine is 2774(L) × 500(W) × 1675(H) mm, and which consists of three parts as input, steam, delivery. Input part looks after half of cylinder which can manage of dropping quantity of mixed materials using a tap and knob. Mixed materials can be steamed moving through conveyer belt over steaming bin. Steaming bin can contain water of 10 liter, and water level sensor detects the water quantity so that the level of water is below than 3 liter, alarm rings then fill up the water to 10 liter. Steam bin has electric heating elements and its target temperature is 110°C. Conveying belt over the steam bin moves 1.5 rotates per second which is changeable speed depends on the condition of mixed materials. Thin and long rice paper moves on conveying belt then had cut using a plastic cutter. Processed rice paper moves to output part. Mixed materials with rice powder, starch powder and water has different physical properties. Rice powder 1,000g, tapioca starch 200g, and 60°C water 1,800 ㎖ can be produced rice paper quality. However, further study is necessary to find an optimal recipe using a few rice varieties and starches.

Entropy Minimization for Groupwise Planar Shape Co-alignment and its Applications

Youngwook Kee,Lee, Han S.,Junho Yim,Cremers, Daniel,Junmo Kim IEEE 2015 IEEE signal processing letters Vol.22 No.11

<P>We propose an information-theoretic criterion, entropy estimate, for the joint alignment of a group of shape observations drawn from an unknown shape distribution. Employing a nonparametric density estimation technique with implicit shape representation, we minimize the entropy estimate with respect to the pose parameters of similarity transformations based on gradient descent optimization for which we provide implementation details. We demonstrate the capacity of our approach in numerous experiments with an application of building a shape prior to prostate MR image segmentation.</P>

Physical Characteristics of Rice Dumpling Skin from Different Rice Varieties

Youngwook Seo,Youngju Lee,Eunmi Kim,Ahyeong Lee,Giyoung Kim 한국산업식품공학회 2019 학술대회 및 심포지엄 Vol.2019 No.10

Classification of behavioral signs of the mares for prediction of the pre-foaling period

Youngwook Jung,Heejun Jung,Yongseok Jang,Duhak Yoon,Minjung Yoon 한국동물생명공학회(구 한국동물번식학회) 2021 Journal of Animal Reproduction and Biotechnology Vol.36 No.2

In horse management, the alarm system with sensors in the foaling period enables the breeder can appropriately prepare the time of the parturition. It is important to prevent losses by unpredictable parturition because there are several high risks such as dystocia and the death of foals and mares during foaling. However, unlike analysis in the alarm system that detects specific motions has been widely performed, analysis of classification following specific behavior patterns or number needs to be more organized. Thus, the objective of this study is to classify signs of the specific behaviors of the mares for the prediction of pre-foaling behaviors. Five Thoroughbred mares (9-20 yrs) were randomly selected for observation of the prefoaling behaviors. The behaviors were monitored for 90 min that was divided into three different periods as 1) from -90 to -60 min, 2) from -60 to -30 min, 3) from -30 min to the time for the discharge of the amniotic fluid, respectively. The behaviors were divided into two different categories as state and frequent behaviors and each specific behavioral pattern for classification was individually described. In the state behaviors, the number of mares in the standing of the foaling group (3.17 ± 0.18b) at period 3 was significantly higher than the control group (1.67 ± 0.46a). In contrast, the number of the mares in the eating of the foaling group (1.17 ± 0.34b) at period 3 was significantly lower than the control group (3.33 ± 0.46a). In the frequent behaviors, the weaving of the foaling group was significantly higher than the control group, and looking at the belly of the foaling group was significantly lower than the control group. In period 2, defecation, weaving, and lowering the head of the foaling group were significantly higher than the control group, respectively. In period 3, sitting down and standing up, pawing, weaving, and lowering the head in the foaling group were also significantly higher than the control group. In conclusion, the behavior is significantly different in foaling periods, and the prediction of foaling may be feasible by the detection of the pre-foaling behaviors in the mares.

Analysis of the static yield stress for giant electrorheological fluids

Youngwook P. Seo,최형진,서용석 한국유변학회 2017 Korea-Australia rheology journal Vol.29 No.3

Cheng et al. (2010)'s experimental results for the static yield stress of giant electrorheological (GER) fluids over the full range of electric field strengths were reanalyzed by applying Seo’s scaling function which could include both the polarization and the conductivity models. The Seo’s scaling function could correctly fit the yield stress behavior of GER suspensions behavior after if a proper normalization of the yield stress data was taken which collapse them onto a single curve. The model predictions were also contrasted with recently proposed Choi et al.’s scaling function to rouse the attention for a proper consideration of the GER fluid mechanisms.