• Title/Summary/Keyword: time-history analyses

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A study on the scientific background of thinking of Kang Youwei and a stage of 'Tianyou' (강유위(康有爲) 사상의 과학적 배경과 '천유경계(天遊境界)')

  • Han, Sung Gu
    • The Journal of Korean Philosophical History
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    • no.27
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    • pp.197-222
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    • 2009
  • The Reform Movement(戊戌變法) of 1898 was a boundary tablet of modern history of science and technology which inherited the past and ushered in the future. Kang Youwei(康有爲), as a leader, his scientific thoughts opened up the way of Chinese enlightenity campaign and pushed the development of Chinese modem science and had an important position in modem history of scientific thoughts. The dissertation analyses the source, establishment and content of Kang Youwei. Kang Youwei developed the useful and discarded the useless of the view of implement science held by the Westernized Party, undertook a deep and throughout thinking on the nature of science, had cognition of scientific methods and spirit, by which he criticized negative proneness of ancient Chinese views of science. He put forwards a series of practical suggestions on political reform that provided a solid guarantee and support in system for scientific development. Kang Youwei rooted in the soil of Chinese traditional academic culture, but also western learning in modern western civilization. Kang go through Westernization Movement since the in-depth study of Western natural and inevitable outcome of the social sciences, are giving to science and technology. Although he was originally of Western "science" has a lot of misunderstandings and prejudices, but these shallow hazy perceptual knowledge, his view of science which constitutes the basis of the formation. In the course of scientific inquiry, Kang has begun to explore the essence of scientific development. He has a gut feeling that behind the scientific discovery of the existence of a force, which is the scientific truth and is used to grasp the scientific method. After contact with the Western world, with the traditional "Heaven(天)", and modern Chinese intellectuals began to "axiom(公理)" to recover his traditional "Heaven" of the new understanding is reflected mainly in "Zhutianjiang(諸天講)". "Zhutianjiang" is the Kang Yuwei in the absorption of traditional astronomy knowledge base, will the traditional arithmetic, as well as Buddhism and the West since the twentieth century, new knowledge of astronomy combines written. Kang while recognizing that scientific instruments, is nothing more than an extension of the role of the human senses and make the "Dao(道)" is more clear, but the "artifacts(器物)" caused by the inherent limitations of the limited nature of human knowledge, which is "Heaven" boundless nature of the broad terms, refused to concede defeat to. In reality, the activities of political reform, he gradually recognize this real-world helpless, and he recognized that the real world to achieve common ground of social ideal is impossible, so he chose comfort in life that people really get a stage of "Tianyou(天遊)". This is the cause that his writing "Datongshu(大同書)", at the same time, followed by writing "Zhutianjiang" talk "Tianyou".

A Dynamic Study of Women's Labor Market Transitions: Career Interruptions and its Determinants (여성의 동태적 노동공급 - 취업연속성과 첫 노동시장 퇴출행태를 중심으로 -)

  • 김영옥
    • Korea journal of population studies
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    • v.25 no.2
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    • pp.5-40
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    • 2002
  • Using detailed data of women's work history, this study analyses the transition process between employment and non-employment over the life history in order to identity individual and structural determinants in the processes. Korean women comprise very heterogeneous groups in terms of work continuity: one group having a continuous work history and another having an interrupted work experience. While 4.0% of total women have stayed in the labor market since leaving school, 17.3% have not worked outside at all and remaining 87.9% have experienced into and out of the labor market at least once. On the average, the cumulated time of employment per woman is 8.2 years and the cumulated time of unemployment is 13.1 years. Thus Korean women work a total of only 38.5% of their whole lifetime after leaving school. We can conclude that the increase of the employment rate of married women in Korea since the 1970s has been due to the increase of the new entrants with short or little working careers into the labor market, not to the increase of women's work continuity on the whole. A women's educational achievement does not seem to be positively related to employment duration, contrary to the suggestion of the human capital theory, Rather, family variables, especially the existence of the child under 6 yens old, is a more significant determining factor for an individual's exit from employment. And there is little difference among different age cohorts which implies little improvement in the employment continuity of younger women. This study also documents the importance of structural variables, such as the type of occupation, as significant determining factors for the hazard rate. Specially women with professional jobs tend to stay longer in the labor market. Therefore, women's entry into more professional occupations is expected to contribute to the continuity of employment. Our results also show that duration-dependence is not spurious. When unobserved heterogeneity is controlled, the negative relation between the rate from employment and the duration of employment does not disappear.

A Study on the ROK Army Leadership for promoting Jointness (합동성 증진을 위한 한국군 리더십 연구)

  • Jin, Jae-Yeoul
    • Korea and Global Affairs
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    • v.1 no.2
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    • pp.209-242
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    • 2017
  • The purpose of this study is to contribute to enhancing spiritual combat power as the core of intangible combat power in Korean armed forces through analyses and suggestions on Admiral Yi Sun-sin's leadership for four major sweeping victories based upon jointness which effectively integrates tangible and intangible combat power in armed forces to maximize the synergy of fighting power. As our armed forces has improved their military structure in the dimension of hardwares so as to enhance their efficiency, according to the results of analyzing the process to promote the jointness between our armed forces and our allied powers in the dimension of softwares supporting such hardware dimensions, it was necessary to innovate the system for reinforcing future-oriented spiritual combat power as well as all the tasks related to leadership as the core of intangible combat power jointly and harmoniously. In order to derive tasks about the leadership of Korean armed forces in the dimension of softwares which should be combined with military structural reform for strengthening spiritual combat power for national defense, this study selected research questions linked with jointness. That is, (1) what is the core of military leadership in Western advanced countries in the age of jointness? (2) What are the contemporary illuminations or implications of Korean leaderships through Admiral Yi Sun-sin's war history? Then, this study analyzed literature reviews, this author's field interviews in the time of war participation, and leadership war history focusing on Admiral Yi Sun-sin's leadership for four major sweeping victories. According to the results of these analyses, this study extracted (1) the strategic leadership to predict and prepare the future, (2) the leadership of integration to create synergy effects, and (3) the leadership of knowledge to be practiced focusing on combats. In addition, in order to reinforce spiritual combat power based upon jointness, (1) it is necessary to precede in-depth and substantial leadership diagnosis for enhancing jointness. (2) It is necessary to embody national defense reform as well as integration for jointness improvement after scientifically comparing and analyzing the differentiation and integration between the Ministry of National Defense, army-navy-air force leadership centers, and PKO centers. (3) It is necessary to promote the merger and abolition between institutions related to intangibale combat power under the Ministry of National Defense.

Postoperative Arrhythmias after Open Heart Surgery in Adults (성인에서의 개심술후 부정맥)

    • Journal of Chest Surgery
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    • v.31 no.11
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    • pp.1056-1062
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    • 1998
  • Background: We prospectively investigated types, incidences, and risk factors for arrhythmias after open heart surgery in adults. Materials and methods: From June 1994 to May 1995, we performed 302 cases of adult cardiac surgery at our department. This study group consisted of 150 men and 152 women, with a mean age of 43.9±28.0(range 16 to 75)years. We included all the patients irrespective of their operative types or disease entities. Results: The overall incidence of arrhythmias after open heart surgery in adults was 58.3%. The incidence of postoperative arrhythmias for redo-valvular heart surgery was 77.8%, and those for simple valvular procedure, coronary artery bypass surgery, aortic surgery, and congenital heart disease were 70.8%, 45.3%, 40.0%, and 29.5%, respectively. Eight out of twelve risk factors showed statistical significance for the development of postoperative arrhythmias. They were preoperative history of arrhythmias, antiarrhythmic drug medication, previous cardiac surgery, larger left ventricular end-diastolic, end-systolic dimension, left atrial dimension on preoperative echocardiogram, longer cardiopulmonary bypass time and aortic cross clamping time. Univariated analyses for age and types of cardioplegic solution did not show statistical significance. Conclusions: Prospective study on postoperative arrhythmias occurrence, treatment and prevention of is warrauted to draw more clear conclusion.

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Drop Impact Analysis of Outside Cooling Unit Package of System Air-Conditioner and Experimental Verification (시스템 에어컨 실외기 포장품의 낙하충격해석 및 시험적 검증)

  • Kim, Hyung-Seok;Lee, Boo-Yoon;Lee, Sanghoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.111-116
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    • 2018
  • This research examines the drop impact of an external cooling unit package of an air conditioner system. The packaging is composed of a shock-absorbing material, which protects the package contents by absorbing the impact energy and other parts for fixture. Accurate quantification of the impact acceleration experienced by the package contents is necessary to design an effective packaging with minimal volume and sufficient shock absorbing capacity. Explicit time integration was used for the drop impact analyses. A finite element model of the package was constructed, material testing and material model selection were carried out, and sensors for data acquisition were modeled to obtain accurate simulation results. The results were compared with real physical test data. Due to imprecise modeling of the damping, the acceleration and strain values predicted by the simulation were larger than those from physical test. However, the trend of the history data and the peak deceleration value in the direction of impact showed good agreements. Thus, the analysis model and scheme are suitable for the design of an air conditioner cooling unit package.

Development of Efficient Seismic Analysis Model using 2D T-Shape Rigid-body for Wall-Frame Structures with a Central Core (이차원 T형강체를 이용한 중심코어를 가진 전단벽-골조 구조물의 효율적인 지진해석모델 개발)

  • Park, Yong-Koo;Lee, Dong-Guen;Kim, Hyun-Su
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.1
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    • pp.9-17
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    • 2013
  • In this study, an efficient analytical model for the dynamic analysis of tall buildings with a shear wall-frame structural system has been proposed. A shear wall-frame structural system usually consists of a core wall showing flexural behavior and a frame presenting shear behavior. Therefore, the deformed shape of the shear wall-frame structural system is shown by the combination of flexural mode and shear mode. These characteristics should be considered when an efficient analytical model is developed. To this end, the effect of shear wall and frame on the dynamic behavior of a tall building with a dual system has been separately investigated. In this study, the structural characteristics of a separated individual shear wall model and the frame model without shear wall has been evaluated. In order to consider the effect of the shear wall in the frame model without shear wall, a rigid body was used instead of the shear wall. Each equivalent model for the separated shear wall part and frame part has been independently developed and two equivalent models were then combined to create an efficient analytical model for tall buildings with a shear wall-frame structural system. In order to verify the efficiency and accuracy of the proposed method, time history analyses of tall buildings with a shear wall-frame system were performed. Based on analytical results, it has been confirmed that the proposed method can provide accurate results, requiring significantly reduced computational time and memory.

A Study on Intelligent Self-Recovery Technologies for Cyber Assets to Actively Respond to Cyberattacks (사이버 공격에 능동대응하기 위한 사이버 자산의 지능형 자가복구기술 연구)

  • Se-ho Choi;Hang-sup Lim;Jung-young Choi;Oh-jin Kwon;Dong-kyoo Shin
    • Journal of Internet Computing and Services
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    • v.24 no.6
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    • pp.137-144
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    • 2023
  • Cyberattack technology is evolving to an unpredictable degree, and it is a situation that can happen 'at any time' rather than 'someday'. Infrastructure that is becoming hyper-connected and global due to cloud computing and the Internet of Things is an environment where cyberattacks can be more damaging than ever, and cyberattacks are still ongoing. Even if damage occurs due to external influences such as cyberattacks or natural disasters, intelligent self-recovery must evolve from a cyber resilience perspective to minimize downtime of cyber assets (OS, WEB, WAS, DB). In this paper, we propose an intelligent self-recovery technology to ensure sustainable cyber resilience when cyber assets fail to function properly due to a cyberattack. The original and updated history of cyber assets is managed in real-time using timeslot design and snapshot backup technology. It is necessary to secure technology that can automatically detect damage situations in conjunction with a commercialized file integrity monitoring program and minimize downtime of cyber assets by analyzing the correlation of backup data to damaged files on an intelligent basis to self-recover to an optimal state. In the future, we plan to research a pilot system that applies the unique functions of self-recovery technology and an operating model that can learn and analyze self-recovery strategies appropriate for cyber assets in damaged states.

A Study to Construct a Decision-making Checklist through the Analysis of Past Disaster Case (과거 재난사례분석을 통한 재난 의사결정 체크리스트 구성에 관한 연구)

  • Seo, Kyungmin;Rheem, Sankyu;Choi, Woojung
    • Journal of the Society of Disaster Information
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    • v.16 no.2
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    • pp.248-266
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    • 2020
  • Purpose: The purpose of this study is to create a checklist for each type of disaster and to suggest a method for establishing an appropriate response system and making accurate and rapid decision-making. Method: In order to derive checklist factors, previous case analyses (Tropical Storm Rusa (2002), Typhoon Maemi (2003), and Typhoon Chaba (2016) were conducted for typhoon disaster. Grouping was conducted to derive checklist factors by analyzing general status (climate and weather) information and characteristics by case. Result: The case study was divided into national level and county level. In terms of national unit, eight forecasts were included: weather forecast, typhoon landing status, typhoon intensity, typhoon radius, central pressure, heavy rain conditions, movement speed, and route. Local governments should reflect regional characteristics, focusing on the presence or absence of similar typhoons (paths) in the past, typhoon landing time, regional characteristics, population density, prior disaster recovery, recent disaster occurrence history, secondary damage, forecast warning system. A total of eight items were derived. Conclusion: In the event of a disaster, decision making will be faster if the checklist proposed in this study is used and applied. In addition, it can be used as the basic data for disaster planners' response plans in case of disasters, and it is expected to be a more clear and quick disaster preparedness and response because it reflects local characteristics.

Evaluation for Progressive Collapse Resistance of a RC Flat Plate System Using the Static and Dynamic Analysis (정적 및 동적 해석을 통한 철근콘크리트 무량판 구조의 연쇄 붕괴 저항 성능 평가)

  • Lee, Seon-Woong;Shin, Sung-Woo
    • Journal of the Korea Concrete Institute
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    • v.23 no.2
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    • pp.245-252
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    • 2011
  • Currently, the design guidelines for the prevention of progressive collapse are not available in Korea due to the lack of study efforts in progressive collapse resistance evaluation of RC flat plate system. Therefore, in this study, three types of analysis were conducted to evaluate the progressive collapse resistance of a RC flat plate system. A linear static analysis was carried out by comparing the demand-capacity ratio (DCR) differences of the systems using the alternate load path method, which is the guideline of GSA. A dynamic behavior was investigated by checking the vertical deflection after removal of the column using the linear dynamic analysis. Lastly, a maximum load factor was investigated using the nonlinear static analysis. The finite element (FE) analyses were conducted using various parameters to analyze the results obtained using effective beam width (EB) model and plate element FEM (PF) model. This study results showed that the strength contributions of the slab in the EB models are underestimated compared to those obtained from the PF models. Therefore, a detailed FE analysis considering the slab element is required to thoroughly estimate the progressive collapse resisting capacity of flat plate system. The scenario of the corner column (CC) removal is the most dangerous conditions where as the scenario of the inner column (IC) removal is the least dangerous conditions based on the consideration of various parameters. The analysis results will allow more realistic evaluations of progressive collapse resistance of RC flat plate system.

Seismic Performance of Bridges with the Modeling of Expansion Rocker Bearings (라커베어링 모델에 따른 교량의 지진거동)

  • Choi, Eunsoo
    • Journal of Korean Society of Steel Construction
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    • v.14 no.6
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    • pp.755-763
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    • 2002
  • Multispan simply supported bridges and multispan continuous bridges take a large portion of bridges in Central and Southeastern United Sates. The superstructure of the bridges are supported by steel rocker bearings. In general, the rocker bearings are modeled with ideal rollers or Coulomb fricition in seismic analysis. However, the rocker bearings have rocking action on pintles after rolling some distance. This rocking action may have considerable effect on the seismic performance of bridges. This study compares the effect of expansion rocker bearings models on a multispan simply supported and a multispan continuous bridge. Since the ideal roller model produces larger responses than the rocking model, its use is undesirable. However, the fricition and hardening model does not have much difference from the responses of the rocking model. In addition, the use of the tow models is convenient in seismic analyses of bridges. Although the rocking model can obtain more exact responses, its behavior is complicated and it may induce the conversion problem in time history analysis because it includes the abrupt changing of stiffiness. The friction and hardening model of expansion rocker bearings is therefore recommended in sesismic analysis.