• Title/Summary/Keyword: Critical History

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Generation of critical and compatible seismic ground acceleration time histories for high-tech facilities

  • Hong, X.J.;Xu, Y.L.
    • Structural Engineering and Mechanics
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    • v.26 no.6
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    • pp.687-707
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    • 2007
  • High-tech facilities engaged in the production of semiconductors and optical microscopes are extremely expensive, which may require time-domain analysis for seismic resistant design in consideration of the most critical directions of seismic ground motions. This paper presents a framework for generating three-dimensional critical seismic ground acceleration time histories compatible with the response spectra specified in seismic design codes. The most critical directions of seismic ground motions associated with the maximum response of a high-tech facility are first identified. A new numerical method is then proposed to derive the power spectrum density functions of ground accelerations which are compatible with the response spectra specified in seismic design codes in critical directions. The ground acceleration time histories for the high-tech facility along the structural axes are generated by applying the spectral representation method to the power spectrum density function matrix and then multiplied by envelope functions to consider nonstationarity of ground motions. The proposed framework is finally applied to a typical three-story high-tech facility, and the numerical results demonstrate the feasibility of the proposed approach.

An Analysis of the 'Mietskaserne' Blockhousing in the late 19th Century in Berlin -Remodeling of Hackesche Hoefe- (19세기 베를린 '미츠카제리네' 블록하우징에 관한 고찰 - Hackesche Hoefe 리모델링을 중심으로 -)

  • Lee, Myoung-Ju
    • Journal of architectural history
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    • v.13 no.1 s.37
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    • pp.71-81
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    • 2004
  • The $18^{th}$ century's Industrial Revolution brought about influx of commerce, industry, and agricultural population into the urban areas, entering the $19^{th}$ century. Quality of rural communities declined, and the exploding population in the cities gave rise to various problems. 'Mietskaserne' Blockhousing was constructed by the 'Hobrechtplan', but led to social problems such as poor living conditions, insufficient sunshine due to overcrowding, slums due to incomplete urban infrastructure, epidemics, and so on. Starting in the early $20^{th}$ century, Berlin has driven forward a remodeling plan under the motto of 'critical reconstruction (kritische Rekonstruktion)'. It is performed in the place, which represents the vicissitudinous history of Berlin with site plans coexisting past with presence, using modern vocabulary of architectural forms. Reconstructing a city is a process which not only raises the economic value of each building consisting a city, but also a redevelopment process that brings out cultural value of an era. When a new era emerges buildings get reconstructed or rebuilt, and thereby form the identity of a city by reflecting its society, culture, politics, economy, and history. Old German architecture were not destroyed or rebuilt recklessly just by the fact that they are functionally or aesthetically outdated. Each building is treated as precious cultural heritage reflecting the history. This is how Berlin is being transformed today.

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Climate Change and Individual Life History (기후변화와 개체의 생활사)

  • Lee, Who-Seung
    • Ocean and Polar Research
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    • v.34 no.3
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    • pp.275-286
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    • 2012
  • Over the last 20 years there have been more than 3000 peer-reviewed papers relating to climate change and biodiversity published, and still the numbers are increasing. However, most studies focused on the impacts of climate change at population or community levels, and the results invariably reveal that there has been, or will be, a negative effect on the structure and pattern of biodiversity. Moreover, the climate change models and statistical analyses used to test the impacts are only newly developed, and the analyses or predictions can often be misled. In this review, I ask why an individual's life history is considered in the study how climate change affects biodiversity, and what ecological factors are impacted by climate change. Using evidence from a range of species, I demonstrate that diverse life history traits, such as early growth rate, migration/foraging behaviour and lifespan, can be shifted by climate change at individual level. Particularly I discuss that the optimal decision under unknown circumstance (climate change) would be the reduction of the ecological fitness at individual level, and hence, a shift in the balance of the ecosystem could be affected without having a critical impact on any one species. To conclude, I summarize the links between climate changes, ecological decision in life history, the revised consequence at individual level, and discuss how the finely-balanced relationship affects biodiversity and population structure.

Evaluation of the Relationship Between Possible Earthquake Time History Shape Occurring in a Target Fault Using Pseudo-Basis Function (유사기저함수를 사용한 대상 단층에서 발생 가능 지진파 형태 사이의 관계 표현 방법 개발 및 포항 단층과 경주 단층 발생 지진에의 적용)

  • Park, Hyung Choon;Oh, Hyun Ju
    • Journal of the Earthquake Engineering Society of Korea
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    • v.27 no.3
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    • pp.139-145
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    • 2023
  • It is essential to determine a proper earthquake time history as a seismic load in a seismic design for a critical structure. In the code, a seismic load should satisfy a design response spectrum and include the characteristic of a target fault. The characteristic of a fault can be represented by a definition of a type of possible earthquake time history shape that occurred in a target fault. In this paper, the pseudo-basis function is proposed to be used to construct a specific type of earthquake, including the characteristic of a target fault. The pseudo-basis function is derived from analyzing the earthquake time history of specific fault harmonic wavelet transform. To show the feasibility of this method, the proposed method was applied to the faults causing the Gyeong-Ju ML5.8 and Pohang ML5.3 earthquakes.

A Case of Giant Cell Interstitial Pneumonia (거대세포 간절성 폐렴(Giant Cell Interstitial Pneumonia) 1예)

  • Kang, Kyeong-Woo;Park, Sang-Joon;Suh, Gee-Young;Han, Joung-Ho;Chung, Man-Pyo;Kim, Ho-Joong;Kwon, O-Jung;Rhee, Chong-H.;Choi, Jae-Wook
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.2
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    • pp.260-267
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    • 2000
  • Giant cell interstitial pneumonia. a synonym for hard metal pneumoconiosis, is a unique form of pulmonary fibrosis resulting from an exposure to hard metal dust. A case of biopsy-proved giant cell interstitial pneumonia in the absence of appropriate history of exposure to hard metal dust is reported. The patient presented with clinical features of chronic interstitial lung disease or idiopathic pulmonary fibrosis. He worked in a chemical laboratory at a fertilizer plant, where he had been exposed to various chemicals such as benzene and toluene. He denied having any other hobby in his house or job at work, which may have exposed him hard metal dust. High-resolution CT scan revealed multi-lobar distribution of ground glass opacity with peripheral and basal lung predominance. The retrieved fluid of bronchoalveolar lavage contained asbestos fiber and showed neutrotphil predominance. Surgical lung biopsy was performed for a definite diagnosis. Lung specimen showed alveolar infiltration of numerous multinucleated giant cells with mild interstitial fibrosis. Upon detailed examination of the lung tissue, one asbestos body was found. An analysis for mineral contents in lung tissue was performed. Compared with the control specimen, the amount of cobalt and several hard metal components in the lung tissue of this patient was ten times higher. We speculated that the inconsistency between occupational history and the findings of pathologic and mineralogical analyses could be explained by the difference in individual immunologic reactivity to hard metal dust despite the relatively small amount of unrecognized environmental exposure(ED: It's hard to understand what this phrase is trying to say).

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Exhaled Nitric Oxide in Patients with Stable Chronic Obstructive Pulmonary Disease: Clinical Implications of the Use of Inhaled Corticosteroids

  • Jo, Yong Suk;Choe, Junsu;Shin, Sun Hye;Koo, Hyeon-Kyoung;Lee, Won-Yeon;Kim, Yu Il;Ra, Seung Won;Yoo, Kwang Ha;Jung, Ki Suck;Park, Hye Yun;Park, Yong-Bum
    • Tuberculosis and Respiratory Diseases
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    • v.83 no.1
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    • pp.42-50
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    • 2020
  • Background: Fractional exhaled nitric oxide (FeNO) is regarded as a potential biomarker for identifying eosinophilic inflammation. We aimed to evaluate the clinical implication of FeNO and its influence on inhaled corticosteroids (ICS) prescription rate in Korean chronic obstructive pulmonary disease (COPD) patients. Methods: FeNO level and its association with clinical features were analyzed. Changes in the prescription rate of ICS before and after FeNO measurement were identified. Results: A total of 160 COPD patients were divided into increased (≥25 parts per billion [ppb], n=74) and normal (<25 ppb, n=86) FeNO groups according to the recommendations from the American Thoracic Society. Compared with the normal FeNO group, the adjusted odds ratio for having history of asthma without wheezing and with wheezing in the increased FeNO group were 2.96 (95% confidence interval [CI], 1.40-6.29) and 4.24 (95% CI, 1.37-13.08), respectively. Only 21 out of 74 patients (28.4%) with increased FeNO prescribed ICS-containing inhaler and 18 of 86 patients (20.9%) with normal FeNO were given ICS-containing inhaler. Previous exacerbation, asthma, and wheezing were the major factors to maintain ICS at normal FeNO level and not to initiate ICS at increased FeNO level. Conclusion: Increased FeNO was associated with the history of asthma irrespective of wheezing. However, FeNO seemed to play a subsidiary role in the use of ICS-containing inhalers in real-world clinics, which was determined with prior exacerbation and clinical features suggesting Th2 inflammation.

Dynamic Per-Branch History Length Fitting for High-Performance Processor (고성능 프로세서를 위한 분기 명령어의 동적 History 길이 조절 기법)

  • Kwak, Jong-Wook;Jhang, Seong-Tae;Jhon, Chu-Shik
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.44 no.2 s.314
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    • pp.1-10
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    • 2007
  • Branch prediction accuracy is critical for the overall system performance. Branch miss-prediction penalty is the one of the significant performance limiters for improving processor performance, as the pipeline deepens and the instruction issued per cycle increases. In this paper, we propose "Dynamic Per-Branch History Length Fitting Method" by tracking the data dependencies among the register writing instructions. The proposed solution first identifies the key branches, and then it selectively uses the histories of the key branches. To support this mechanism, we provide a history length adjustment algorithm and a required hardware module. As the result of simulation, the proposed mechanism outperforms the previous fixed static method, up to 5.96% in prediction accuracy. Furthermore, our method introduces the performance improvement, compared to the profiled results which are generally considered as the optimal ones.

Branch Prediction with Speculative History and Its Effective Recovery Method (분기 정보의 추측적 사용과 효율적 복구 기법)

  • Kwak, Jong-Wook
    • The KIPS Transactions:PartA
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    • v.15A no.4
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    • pp.217-226
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    • 2008
  • Branch prediction accuracy is critical for system performance in modern microprocessor architectures. The use of speculative update branch history provides substantial accuracy improvement in branch prediction. However, speculative update branch history is the information about uncommitted branch instruction and thus it may hurts program correctness, in case of miss-speculative execution. Therefore, speculative update branch history requires suitable recovery mechanisms to provide program correctness as well as performance improvement. In this paper, we propose recovery logics for speculative update branch history. The proposed solutions are recovery logics for both global history and local history. In simulation results, our solution provides performance improvement up to 5.64%. In addition, it guarantees the program correctness and almost 90% of additional hardware overhead is reduced, compared to previous works.

Oral History Research and Human Subject Research on Bioethics and Safety Law (구술사 연구와 「생명윤리법」의 인간대상연구)

  • Lee, Hosin
    • Journal of Korean Society of Archives and Records Management
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    • v.17 no.3
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    • pp.1-21
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    • 2017
  • Oral history research is carried out through collecting information about a living person. The data collected from an oral history project is not a mere fact or a mass of information but accounts of persons who reveal their own personalities. For this reason, oral history research and data collection and the use of such data must be based on rigorous ethical standards. The Bioethics and Safety Law shares a similar view on human subject research, and the Institutional Review Boards includes human subject research as a subject of review and management. However, the Bioethics and Safety Law's protection of personalities and human rights focuses on life sciences methodologies, which are not suitable for qualitative research, such as an oral history of a value oriented and critical approach to human beings. This study examines the details of the Bioethics and Safety Law related to human subject research and the problems that may arise when this law is applied to subjects in humanities and social sciences such as oral history. Through this study, alternative methodologies, which can be used for oral history research, while maintaining academic autonomy, are suggested.

Teaching Social Justice through Three Time Periods of Sweatshop History

  • Garrin, Ashley;Marcketti, Sara
    • International Journal of Costume and Fashion
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    • v.15 no.1
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    • pp.75-85
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    • 2015
  • Due to the plethora of political, economic, and social challenges experienced on a global scale in the 21st century, students need to be concerned with more than their immediate surroundings (Johnson, 2005). When implemented in an educational setting, topics encompassing social justice may provide students with the confidence and skills to become "reflective, moral, caring, and active citizens in a troubled world" (Banks and Banks, 2009, p.5). The purpose of this article was to provide examples of undergraduate lessons focused on sweatshop conditions within three time periods of United States history that incorporate social justice into the course curriculum. By implementing social justice lessons into the curriculum, students can engage in critical reading, writing, and thinking about injustices faced by society. Girded with knowledge of past oppression within the apparel industry, students may become actively engaged in challenging social injustices in our world.