• Title/Summary/Keyword: Design-time history

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Performance based assessment for tall core structures consisting of buckling restrained braced frames and RC walls

  • Beiraghi, Hamid;Alinaghi, Ali
    • Earthquakes and Structures
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    • v.21 no.5
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    • pp.515-530
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    • 2021
  • In a tall reinforced concrete (RC) core wall system subjected to strong ground motions, inelastic behavior near the base as well as mid-height of the wall is possible. Generally, the formation of plastic hinge in a core wall system may lead to extensive damage and significant repairing cost. A new configuration of core structures consisting of buckling restrained braced frames (BRBFs) and RC walls is an interesting idea in tall building seismic design. This concept can be used in the plan configuration of tall core wall systems. In this study, tall buildings with different configurations of combined core systems were designed and analyzed. Nonlinear time history analysis at severe earthquake level was performed and the results were compared for different configurations. The results demonstrate that using enough BRBFs can reduce the large curvature ductility demand at the base and mid-height of RC core wall systems and also can reduce the maximum inter-story drift ratio. For a better investigation of the structural behavior, the probabilistic approach can lead to in-depth insight. Therefore, incremental dynamic analysis (IDA) curves were calculated to assess the performance. Fragility curves at different limit states were then extracted and compared. Mean IDA curves demonstrate better behavior for a combined system, compared with conventional RC core wall systems. Collapse margin ratio for a RC core wall only system and RC core with enough BRBFs were almost 1.05 and 1.92 respectively. Therefore, it appears that using one RC core wall combined with enough BRBF core is an effective idea to achieve more confidence against tall building collapse and the results demonstrated the potential of the proposed system.

Seismic behavior of liquid storage tanks with 2D and 3D base isolation systems

  • Kilic, Samet;Akbas, Bulent;Shen, Jay;Paolacci, Fabrizio
    • Structural Engineering and Mechanics
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    • v.83 no.5
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    • pp.627-644
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    • 2022
  • In past major earthquakes (1994 Northridge, 1995 Kobe, Chi-Chi 1999, Kocaeli 1999), significant damages occurred in the liquid storage tanks. The basic failure patterns were observed to be the buckling of the tank wall and uplift of the anchorage system. The damages in the industrial facilities and nuclear power plants have caused the spread of toxic substances to the environment and significant fires. Seismic isolation can be used in liquid storage tanks to decouple the structure and decrease the structural demand in the superstructure in case of ground shaking. Previous studies on the use of seismic isolation systems on liquid storage tanks show that an isolation system reduces the impulsive response but might slightly increase the convective one. There is still a lack of understanding of the seismic response of seismically isolated liquid storage tanks considering the fluid-structure interaction. In this study, one broad tank, one medium tank, and one slender tank are selected and designed. Two- and three-dimensional elastomeric bearings are used as seismic isolation systems. The seismic performance of the tanks is then investigated through nonlinear dynamic time-history analyses. The effectiveness of each seismic isolation system on tanks' performance was investigated. Isolator tension forces, modal analysis results, hydrodynamic stresses, strains, sloshing heights and base shear forces of the tanks are compared. The results show that the total base shear is lower in 3D-isolators compared to 2D-isolators. Even though the tank wall stresses, and strains are slightly higher in 3D-isolators, they are more efficient to prevent the tension problem.

Nonlinear Static Analysis for Seismic Performance Evaluation of Multi-Span Bridges Considering Effect of Equivalent SDOF Methods (등가단자유도 방법의 영향을 고려한 다경간 교량의 내진성능 평가를 위한 비탄성 정적해석)

  • Song, Jong-Keol;Nam, Wang-Hyun;Chung, Yeong-Hwa
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3A
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    • pp.473-484
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    • 2006
  • The capacity spectrum method (CSM) can be used to simply estimate the maximum displacement response of the nonlinear structures. To evaluate seismic performance of multi-span bridges using the CSM, the representative response for structural system should be derived from the multi-degree-of-freedom (MDOF) responses by using the equivalent single-degree-of-freedom (ESDOF) method. The ESDOF method is used to calculate the capacity curve of the structural system from the pushover curves of all piers or structural members estimated by the pushover analysis. In order to evaluate an accuracy of ESDOF methods used in the CSM, the maximum displacements estimated by the CSM incorporating the several ESDOF methods are compared to those by the inelastic time-history analysis for several artificial earthquakes corresponding to the design spectrum.

Analysis of Warpage of Fan-out Wafer Level Package According to Molding Process Thickness (몰드 두께에 의한 팬 아웃 웨이퍼 레벨 패키지의 Warpage 분석)

  • Seung Jun Moon;Jae Kyung Kim;Euy Sik Jeon
    • Journal of the Semiconductor & Display Technology
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    • v.22 no.4
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    • pp.124-130
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    • 2023
  • Recently, fan out wafer level packaging, which enables high integration, miniaturization, and low cost, is being rapidly applied in the semiconductor industry. In particular, FOWLP is attracting attention in the mobile and Internet of Things fields, and is recognized as a core technology that will lead to technological advancements such as 5G, self-driving cars, and artificial intelligence in the future. However, as chip density and package size within the package increase, FOWLP warpage is emerging as a major problem. These problems have a direct impact on the reliability and electrical performance of semiconductor products, and in particular, cause defects such as vacuum leakage in the manufacturing process or lack of focus in the photolithography process, so technical demands for solving them are increasing. In this paper, warpage simulation according to the thickness of FOWLP material was performed using finite element analysis. The thickness range was based on the history of similar packages, and as a factor causing warpage, the curing temperature of the materials undergoing the curing process was applied and the difference in deformation due to the difference in thermal expansion coefficient between materials was used. At this time, the stacking order was reflected to reproduce warpage behavior similar to reality. After performing finite element analysis, the influence of each variable on causing warpage was defined, and based on this, it was confirmed that warpage was controlled as intended through design modifications.

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Collapse failure mechanism of subway station under mainshock-aftershocks in the soft area

  • Zhen-Dong Cui;Wen-Xiang Yan;Su-Yang Wang
    • Geomechanics and Engineering
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    • v.36 no.3
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    • pp.303-316
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    • 2024
  • Seismic records are composed of mainshock and a series of aftershocks which often result in the incremental damage to underground structures and bring great challenges to the rescue of post-disaster and the repair of post-earthquake. In this paper, the repetition method was used to construct the mainshock-aftershocks sequence which was used as the input ground motion for the analysis of dynamic time history. Based on the Daikai station, the two-dimensional finite element model of soil-station was established to explore the failure process of station under different seismic precautionary intensities, and the concept of incremental damage of station was introduced to quantitatively analyze the damage condition of structure under the action of mainshock and two aftershocks. An arc rubber bearing was proposed for the shock absorption. With the arc rubber bearing, the mode of the traditional column end connection was changed from "fixed connection" to "hinged joint", and the ductility of the structure was significantly improved. The results show that the damage condition of the subway station is closely related to the magnitude of the mainshock. When the magnitude of the mainshock is low, the incremental damage to the structure caused by the subsequent aftershocks is little. When the magnitude of the mainshock is high, the subsequent aftershocks will cause serious incremental damage to the structure, and may even lead to the collapse of the station. The arc rubber bearing can reduce the damage to the station. The results can offer a reference for the seismic design of subway stations under the action of mainshock-aftershocks.

Exploring the feasibility of developing an education tool for pattern identification using a large language model: focusing on the case of a simulated patient with fatigue symptom and dual deficiency of the heart-spleen pattern (거대언어모델을 활용한 변증 교육도구 개발 가능성 탐색: 피로주증의 심비양허형 모의환자에 대한 사례구축을 중심으로)

  • Won-Yung Lee;Sang Yun Han;Seungho Lee
    • Herbal Formula Science
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    • v.32 no.1
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    • pp.1-9
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    • 2024
  • Objective : This study aims to assess the potential of utilizing large language models in pattern identification education by developing a simulated patient with fatigue and dual deficiency of the heart-spleen pattern. Methods : A simulated patient dataset was constructed using the clinical practice examination module provided by the National Institute for Korean Medicine Development. The dataset was divided into patient characteristics, sample questions, and responses, and utilized to design the system, assistant, and user prompts, respectively. A web-based interface was developed using the Django framework and WebSocket. Results : We developed a simulated fatigue patient representing dual deficiency of the heart-spleen pattern through prompt engineering. To make practical tools, we further implemented web-based interfaces for the examinee's and evaluator's roles. The interface for examinees allows one to examine the simulated patient and provides access to a personalized number for future access. In addition, the interface for evaluators included a page that provided an overview of each examinees' chat history and evaluation criteria in real-time. Conclusion : This study is the first development of an educational tool integrated with a large language model for pattern identification education, which is expected to be widely applied to Korean medicine education.

A Study on Korean Style of Typography - Aesthetic of Simplicity, the Essence of Style (타이포그라피의 한국성 연구 - 단순 미학, 그 고유성의 근거에 대하여)

  • 유정미
    • Archives of design research
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    • v.12 no.1
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    • pp.145-154
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    • 1999
  • With the introduction of digital technology since the late 1970s, we have been shifting from the industrial era into the information age. New communication systems have changed our concept of reality. Korea has a wealthy communication heritage with its own language and alphabet. However, Korean typography today has struggled to keep its originality, and does not hold up well to international standards. Korean contemporary typography is not efficient for communicating. It is not orderly, organised and simple. It has currently become complicated and decorative. Moreover, many young designers are attracted by imitations of western trends. It is now time for Korea to reveal its own identity. How can it develop a new typographic language that is more sympathetic to Korean tradition\ulcorner How will Korean information design produce a contemporary style with international relevance that contributes to world culture\ulcorner This thesis will be developed a new Korean typographic language that relies more on Korean traditions. Simultaneously, in this thesis will be examined Swiss typography as a relevant style for a new Korean typography to incorporate. Swiss typography maintained a similar philosophy to Korean tradition with its emphasis on clarity and simplicity. This study will be explored the potential of creating a contemporary Korean typographic solution which combines the traditions of Korea with the clarity of Swiss typography. The first attitude of the new typographic language should focus on legibility. The second condition of the new typographic philosophy based on the ability of designers is interpretation of context. The third concept of the new language is founded on an objective, rational design attitude. The final mental attitude of the new typographic language should feel a deep obligation to traditions. It is crucial time for Korean alphabet to establish a relevant standard rather than goes uncritically with the international current. Korea has had worthy traditions. It is suggested that the answers to 'good design' lie in the study of Korea's own history. Simultaneously, the research of Swiss design which is a

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The Space Use in the Initial Period of Namsan Park - Focus on the Newspaper Articles from 1883 to 1917 - (남산공원 태동기의 공간별 활용 유형 - 1883~1917년까지 신문기사를 중심으로 -)

  • Seo, Young-Ai;Son, Yong-Hoon
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.31 no.1
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    • pp.28-37
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    • 2013
  • As a symbolic landscape of Seoul, Namsan has undergone not only physical changes but also changes in its human use and characteristics. At this point, research on Namsan, which holds diverse stories that have accumulated over a long period, as a cultural landscape is necessary. In particular, a concrete understanding of the characteristics of the mountain's use in the period of its initiation as a modern park is an important task in research on the history of urban parks. Consequently, the purpose of the present study lies in grasping the use of Namsan at the time of the establishment of Kyongsungbu Namsan Park Design Proposal in 1917 and examining the characteristics per space. The research process was based on the status of the park design plan. The primary source of information came from the analysis of historical newspaper articles. Additional materials including documents, old maps, photographs, postcard materials were also used. The period of the study was 1883 to 1917. This time was the initial period of Namsan Park soon after the opening up of Korea's ports to the world. The major spaces in which Namsan was used as a park encompassed Hanyang Park, Waeseongdae Park, Noin-jeong, Jangchung-dan, and remaining parts of Namsan in a natural state. When the main ways in which each space is used are examined based on the data analyzed, Namsan has been used for purposes including public events, accidents, religious worship, track and field days, field trips, and strolls. When the nature of each of the spaces is determined in terms of the characteristics of their use, these spaces were characterized as community parks, outdoor community spaces, indoor community spaces, sports arenas, and natural parks, among other things. The present study is significant in terms of research on the history of parks for confirming that Namsan in the initial period already served as a modern park for urban activities and grasping the specific urban activities that were engaged in on Namsan.

A Study on the Change of Landscape in Korean Rural Village - From Chosun Dyansty to Olympic Games(1988) - (농촌(農村) 향토(鄕土)마을 경관(景觀)의 변화(變化) - 조선 말기부터 올림픽개최 전(1988)까지 -)

  • Lee, Shi-Young;Jang, Min;Shim, Joon-Young;Heo, Jun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.4
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    • pp.112-119
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    • 2010
  • This study aims at interpreting Korean Rural Landscape by applying the analytical tool thus developed to the lifestyles of ordinary people found in their permanent dwellings both before and after Korea first opened its door to the world in 1896. By so doing, this study hopes to contribute to building a framework with which to understand the tradition of ordinary people by exploring the uniqueness and basic characteristics of Korean Rural Landscape. This study relies primarily on field studies and publications including, without limitation, the televised documentaries, as well as newspapers and scholastic writings and relating to, the agrarian and residential landscapes changed over time. In the Vernacular world, the present does not passively inherit the past. Rather, it is re-born each time, reflecting the society and history of the period. It does not change, but is shaped by the necessities of the period. This may be the reason why there are different Korean Rural Landscapes over a rather short period of time. For instance, the pre-modern Korean Rural Landscape tends to be shaped almost entirely by the nature, while the intention of people begins to find much more expressions in the modern Korean Rural Landscape. As the commodities become more readily available to people thanks to industrialization, such ready availability has brought about changes in the materials used in, as well as functions of, Rural Landscape.

A Study of Functional Performance on Smartphone according to Age Difference (나이 차이에 따른 스마트폰 기능 수행도 연구)

  • Yoon, Cheol-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.3
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    • pp.318-323
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    • 2019
  • In this study, we examined the differences in age among the various functions required for everyday life through smartphone using environment. The subjects were composed of 30 young adults and 30 elderly people. We set up 12 tasks to evaluate the performance of smartphone functions. At the same time, a questionnaire about smartphone usage habits was made. The questionnaire consists of items related to user history and usage habits. ANOVA analysis was performed using Minitab version 14, and statistically significant differences were found in 10 tasks. The result of the actual values for each task showed that the elderly generally took more time to perform all the tasks than the younger ones. Especially, the tendency of the task which requires a lot of keystrokes was revealed. Especially, in the case of a task requiring a lot of keystrokes, the tendency was remarkable. Young adults have found that they use all functions uniformly overall, and the functions used by the elderly were biased toward some functions, such as dialing, text, kakao talk, and searching. These results suggest that young people use smartphones more frequently than elderly people, and as they become accustomed to using smartphones, the time required to perform functions may be shortened. We suggest that it is necessary to design in terms of hardware or software so that the elderly people can input easily and conveniently.