• 대한토목학회논문집
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• 제35권2호
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• pp.255-264
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• 2015

SC (steel plate concrete)구조는 새로운 구조형식으로서 SC구조물의 내진설계에 적용할 수 있는 감쇠비의 규명이 필요하다. 이 연구에서는 실험적 방법을 통해 SC구조의 감쇠비를 분석하였다. 연구를 위하여 SC 전단벽 시편을 제작하고, 대형 진동대를 이용하여 진동시험을 수행하였다. 시험에서 계측한 가속도응답신호는 전달함수로 변환한 후 동적실험모드분석기법을 적용하여 분석하였다. 구조물의 감쇠비는 입력운동의 수준에 따라 달라질 수 있으며, 이 연구의 실험에서 적용한 입력운동의 수준은 시편의 항복강도의 절반보다 낮은 수준으로서 여기서 분석된 구조감쇠비는 약 4%정도이다. 이 연구결과를 고려하여 SC구조물의 운전기준지진에 대한 내진설계에는 4% 감쇠비를 적용할 수 있을 것으로 판단된다.

• Structural Engineering and Mechanics
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• 제37권2호
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• pp.233-251
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• 2011

The seismic provisions of the current edition (2005) of the National Building Code of Canada (NBCC) differ significantly from the earlier edition. The current seismic provisions are based on the uniform hazard spectra corresponding to 2% probability of exceedance in 50 years, as opposed to the seismic hazard level with 10% probablity of exeedance in 50 years used in the earlier edition. Moreover, the current code is presented in an objective-based format where the design is performed based on an acceptable solution. In the light of these changes, an assessment of the expected performance of the buildings designed according to the requirements of the current edition of NBCC would be very useful. In this paper, the seismic performance of a set of six, twelve, and eighteen story buildings of regular geometry and with concrete moment resisting frames, designed for Vancouver western Canada, has been evaluated. Although the effects of non-structural elements are not considered in the design, the non-structural elements connected to the lateral load resisting systems affect the seismic performance of a building. To simulate the non-structural elements, infill panels are included in some frame models. Spectrum compatible artificial ground motion records and scaled actual accelerograms have been used for evaluating the dynamic response. The performance has been evaluated for each building under various levels of seismic hazard with different probabilities of exceedance. From the study it has been observed that, although all the buildings achieved the life-safety performance as assumed in the design provisions of the building code, their performance characteristics are found to be non-uniform.

• 한국지진공학회논문집
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• 제20권7_spc호
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• pp.527-536
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• 2016

This paper investigates seismic damage potential of recent September 12 M5.8 Gyeongju earthquake from diverse earthquake engineering perspectives using the accelerograms recorded at three stations near the epicenter. In time domain, strong motion durations are evaluated based on the accelerograms and compared with statistical averages of the ground motions with similar magnitude, epicentral distance and soil conditions, while Fourier analysis using FFT is performed to identify damaging frequency contents contained in the earthquake. Effective peak ground accelerations are evaluated from the calculated response spectra and compared with apparent peak ground accelerations and the design spectrum in KBC 2016. All these results are used to consistently explain the reason why most of seismic damage in the earthquake was concentrated on low-rise stiff buildings but not quite significant. In order to comparatively appraise the damage potential, the constant ductility spectrum constructed from the Gyeongju earthquake is compared with that of the well-known 1940 El Centro earthquake. Deconvolution analysis by using one accelerogram speculated to be recorded at a stiff soil site is also performed to estimate the soil profile conforming to the response spectrum characteristics. Finally, response history analysis for 39- and 61-story tall buildings is performed as a case study to explain significant building vibration felt on the upper floors of some tall buildings in Busan area during the Gyeongju earthquake. Seismic design and retrofit implications of M5.8 Gyeongju earthquake are summarized for further research efforts and improvements of relevant practice.

• 패션비즈니스
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• 제12권3호
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• pp.99-115
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• 2008

International exchange gets active in nations with the increase of Internet use and heading toward digital age. Thus the communication conveying image of nations effectively plays an important role in an international society. Sports events are regarded as important international exchange events and good opportunities for public relations of one's own country and taken as tools of planting good images in other nations. This study surveyed the concept and history of uniform through the documents and previous studies in order to find the aesthetic characteristics of sportswear uniform applying the image of national ensign and investigates the origin and start time in Korea of selected 6 sports items. As a result of finding the expression way of ensign image and drawing the aesthetic characteristics by analyzing the use and variation of ensign colors, the use of colors other than ensign and reflection of ensign form in collected 60 sports uniforms, this study could draw the symbolical beauty, beauty of variation and beauty of brevity. First, symbolical beauty is the aesthetic characteristics expressing uniforms by using the pattern ensign symbolizes and ensign colors themselves or enlarging a part of ensign. Second, beauty of variation is the aesthetic characteristics creating geometrical new patterns in uniform through the distortion and exaggeration of ensign shape, or transforming the colors themselves of ensign. Third, beauty of brevity is the aesthetic characteristics using other colors only as decorative factor while applying the main colors of ensign to the most part of uniform, or unifying the uniforms with only one color of ensign. As a result of survey, the proportion of the symbolical beauty was highest in summer season and beauty of brevity and beauty of variation followed and the proportion of beauty of variation was highest and the symbolical beauty and beauty of brevity followed after that in winter season. This study found the way of expressing image of one's own country in sports uniform through this article, expecting the exact recognition on sports uniform and the diversity of sports uniform design in which the images of the nation are expressed more variously.

• 한국정보통신학회논문지
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• 제26권6호
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• pp.872-880
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• 2022

본 논문은 패키지 투어에 참여하는 여행자들에게 관광 명소에 대한 정보를 디지털 게임 기반 학습(DGBL) 방식으로 제공하는 모바일 애플리케이션 개발의 핵심인 콘텐츠 관리 시스템(CMS)의 설계 및 구현 결과를 담고 있다. 설계 측면에서 이 CMS는 여행자 정보, 관광 명소 정보, 질문과 점수 구성 등 학습 게임 콘텐츠를 저장하는 데이터베이스, 저장 콘텐츠를 관리하기 위한 웹 애플리케이션, 그리고 모바일 학습 게임과의 연동을 위한 Rest API로 구성된다. CMS 구현을 위해 PHP 프로그래밍 언어와 MySQL 데이터베이스 관리 시스템을 사용하였으며, 성능 평가 결과 CMS와 데이터베이스 간에 0.77초에서 1.4초 사이의 평균 응답 시간을 보여줌을 확인하였다. 본 논문에서 개발한 CMS는 패키지 투어 여행자를 위한 모바일 학습 게임 구현에 실제 적용할 예정이며, 패키지 투어 그룹이 달라지더라도 게임을 재구성할 필요가 없는 융통성을 제공함을 알 수 있다.

• 소성∙가공
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• 제31권1호
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• pp.17-22
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• 2022

Hot stamping is widely used to manufacture structural parts to satisfy requirements of eco-friendly vehicles. Recently, hot forming technology using uncoated steel sheet is being studied to reduce cost and solve patent problems. In particular, research is focused on process technology capable of suppressing the generation of an oxide layer. To evaluate the oxide layer in the hot stamping process, Gleeble testing machine can be used to evaluate the oxide layer by controlling the temperature history and the atmosphere condition. At this time, since cooling by gas injection is impossible to protect the oxide layer on the surface of a specimen, research on a method for securing a quenching speed through natural cooling is required. This paper proposes a specimen shape design method to secure a target quenching speed through natural cooling when evaluating the oxide layer of an un-coated boron steel sheet by Gleeble test. For the evaluation of the oxide layer of the un-coated steel sheet through the Gleeble test, dog-bone and rectangular type specimens were used. In consideration of the hot stamping process, the temperature control conditions for the Gleeble test were set and the quenching speed according to the specimen shape design was measured. Finally, the quenching speed sensitivity according to shape parameter was analyzed through regression analysis. A quenching speed prediction equation was then constructed according to the shape of the specimen. The constructed quenching speed prediction equation can be used as a specimen design guideline to secure a target quenching speed when evaluating the oxide layer of an un-coated boron steel sheet by the Gleeble test.

• Steel and Composite Structures
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• 제47권2호
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• pp.167-184
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• 2023

In this study, a new recentering friction device (RFD) to retrofit steel moment frame structures is introduced. The device provides both self-centering and energy dissipation capabilities for the retrofitted structure. A hybrid performance-based seismic design procedure considering multiple limit states is proposed for designing the device and the retrofitted structure. The design of the RFD is achieved by modifying the conventional performance-based seismic design (PBSD) procedure using computational intelligence techniques, namely, genetic algorithm (GA) and artificial neural network (ANN). Numerous nonlinear time-history response analyses (NLTHAs) are conducted on multi-degree of freedom (MDOF) and single-degree of freedom (SDOF) systems to train and validate the ANN to achieve high prediction accuracy. The proposed procedure and the new RFD are assessed using 2D and 3D models globally and locally. Globally, the effectiveness of the proposed device is assessed by conducting NLTHAs to check the maximum inter-story drift ratio (MIDR). Seismic fragilities of the retrofitted models are investigated by constructing fragility curves of the models for different limit states. After that, seismic life cycle cost (LCC) is estimated for the models with and without the retrofit. Locally, the stress concentration at the contact point of the RFD and the existing steel frame is checked being within acceptable limits using finite element modeling (FEM). The RFD showed its effectiveness in minimizing MIDR and eliminating residual drift for low to mid-rise steel frames models tested. GA and ANN proved to be crucial integrated parts in the modified PBSD to achieve the required seismic performance at different limit states with reasonable computational cost. ANN showed a very high prediction accuracy for transformation between MDOF and SDOF systems. Also, the proposed retrofit showed its efficiency in enhancing the seismic fragility and reducing the LCC significantly compared to the un-retrofitted models.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.51.2-51.2
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• 2015

Understanding interfacial phenomena has been one of the main research issues not only in semiconductors but only in life sciences. I have been trying to meet the atomic scale surface and interface analysis challenges from semiconductor industries and furthermore to extend the application scope to biomedical areas. Optical imaing has been most widely and successfully used for biomedical imaging but complementary ion beam imaging techniques based on mass spectrometry and ion scattering can provide more detailed molecular specific and nanoscale information In this presentation, I will review the 27 years history of medium energy ion scattering (MEIS) development at KRISS and DGIST for nanoanalysis. A electrostatic MEIS system constructed at KRISS after the FOM, Netherland design had been successfully applied for the gate oxide analysis and quantitative surface analysis. Recenlty, we developed time-of-flight (TOF) MEIS system, for the first time in the world. With TOF-MEIS, we reported quantitative compositional profiling with single atomic layer resolution for 0.5~3 nm CdSe/ZnS conjugated QDs and ultra shallow junctions and FINFET's of As implanted Si. With this new TOF-MEIS nano analysis technique, details of nano-structured materials could be measured quantitatively. Progresses in TOF-MEIS analysis in various nano & bio technology will be discussed. For last 10 years, I have been trying to develop multimodal nanobio imaging techniques for cardiovascular and brain tissues. Firstly, in atherosclerotic plaque imaging, using, coherent anti-stokes raman scattering (CARS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) multimodal analysis showed that increased cholesterol palmitate may contribute to the formation of a necrotic core by increasing cell death. Secondly, surface plasmon resonance imaging ellipsometry (SPRIE) was developed for cell biointerface imaging of cell adhesion, migration, and infiltration dynamics for HUVEC, CASMC, and T cells. Thirdly, we developed an ambient mass spectrometric imaging system for live cells and tissues. Preliminary results on mouse brain hippocampus and hypotahlamus will be presented. In conclusions, multimodal optical and mass spectrometric imaging privides overall structural and morphological information with complementary molecular specific information, which can be a useful methodology for biomedical studies. Future challenges in optical and mass spectrometric imaging for new biomedical applications will be discussed.

• 복식
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• 제50권
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• pp.129-144
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• 2000

In the history of the costume of Western Europe one of the most interesting apects is that the silhouette of women's dress has been continuously evolved. There can be various origins in this changing silhouette but the most important origin is that clothes of any period are the reflection of the architectural political religious and economic background against which they are worn they must also be djusted to the texture and design of the materials produced at the time and of course there is always the basic instinct of sex attraction. The changing line in men's and women's clothes has been demanded by each period but man's great active life did not required the development of exaggerated line which could restrict his movements. Exaggeration in men's clothes has usually been confined to accessories only details could be simplified or abandoned altogether in time of action. However Woman has no great concern in these restrivtions and when an era demanded an exaggerated silhouette she developed it to the utmost limit with out any hesitation plunged herself into whalebone cane and steel for the desired line and then later to adapt herself to a changing world just as without any hesitaion abandoned all these artificial props. In this study first of all the origin of the corset and the evolution of silhouette will be chronologically studied and rearranged on the basis of written materials such as text books theses and catalogs which are related to corset In this section the most important backgrounds-social religious and economic-which caused the chages of silhouette will be scrutinized in a time order. Then the shapes and functions of corsets will be looked into in a more detailed way. In addition the materials and decorations which were preferred to achieve the desired silhouette will be examined. Finally underwear which was and has been worn for cleanness protection the shapes of outer clothes and erotic mood will be studied.

• 한국의류산업학회지
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• 제5권5호
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• pp.481-494
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• 2003

The Gamrotenghwa of the Choson Dynasty is a unique genre of buddhist painting in that the destiny of the dead souls and the guidance to nirvana are expressed in reality. More than 50 of the Gamrotenghwa are known to be present, and the lower part of the paintings includes a wide assortment of folk customary scenes reflecting the social life style of the time when the painting was drawn, such as difficulties in life. public life, punishment and war. Changes in the costume of the people shown on the customary scenes of the Gamrotenghwa according to the time based changes in painting style were investigated in this study. The results are summarized in three points. First, the costumes of bureaucrats showed a tendency of preservation without any major changes in the painting. On the other hand, costumes of public and entertainer in the scenes were very close to those worn by the people at that time. The realistic description of public life in the painting may establish the value of the Gamrotenghwa as the historical documents. Second, the costume of the people in the painting showed a dual structure as the social positions; bureaucrats wore various official hats, large coats and belts to expose their social prestige. while the general public wore simple and convenient clothing which is divided into shirt and pants. The dual structure of the costume in the painting is in well accordance with that of the later period of Choson dynasty, suggesting that the customary scenes in the painting represent the social life style of the period. Finally, the customary scenes in the Gamrotenghwa are very variegated. which shows a variety of beauty of wearing even though they look coarse in a sense. The diversity of wearing beauty in the picture may contribute to the recreation of the beauty of shape in the new design of Hanbok.