• 제목/요약/키워드: 구조안정론

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Development and application of integrated indicators for assessing the water resources performance of multi-purpose and water supply dams (댐 용수공급능력 안정성 평가를 위한 통합지표 개발 및 적용)

  • Sung, Jiyoung;Kang, Boosik;Kim, Bomi;Noh, Seongjin
    • Journal of Korea Water Resources Association
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    • v.55 no.9
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    • pp.687-700
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    • 2022
  • For comprehensively assessment the water resources performance of multi-purpose dams and water supply dams in South Korea, a methodology was proposed to utilize the durational reliability along with the integrated auxiliary indicators including resiliency, dimensionless vulnerability, water resource efficiency, specific inflow, and specific water supply. In addition, for the purpose of sustainable dam operation in the future, a plan to grade the water resources performance was presented to periodically evaluate the performance and determine the priority of each dam's structural or non-structural planning according to the evaluation results. As major results, in the case of Sumjingang Dam, the durational reliability was 99.0%, but the integrated auxiliary index was the lowest of 44 points, which was 5th grade. This means that despite the current high reliability, hydrological changes due to future climate change or regional change of water demand-supply balance can have significant impacts on the water resources performances. In contrast, the Chungju Dam with a durational reliability of 93.0%, which is below the average among all multi-purpose dams, shows the 76 points of the integrated auxiliary index, which is 3rd highest following the Soyanggang Dam and the Namgang Dam. Nevertheless, due to the size of the basin, the specific inflow is sufficiently high as 185%, so the actual performance could be evaluated relatively high. The water supply dams designed for a single purpose tend to be evaluated relatively high because they have a high proportion of industrial and municipal water supply and have enough room for the supply capacity.

Management of Infrastructure(Road) Based On Asset Value (자산가치 기반의 교통인프라 유지관리)

  • Dong-Joo Kim;Woo-Seok Kim;Yong-Kang Lee;Hoon Yoo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.3
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    • pp.100-107
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    • 2024
  • Currently, in Korea, due to the rapid aging and deterioration of facilities, the minimum Maintenance Level and Performance Level' of facilities are required by the 'Facility Safety Act' or 'Infrastructure Management Act'. Since infrastructure assets have a long lifespan and the pattern of deterioration over time is complex, it is very difficult to maintain infrastructure as 'minimum maintenance state' or 'minimum performance state' by the current way of management. 'Asset Management' shall be performed not only by a technical perspective, but also by an accounting perspective such as cost and asset value. However, due to lack of awareness of 'asset management' among stakeholder, only technical perspective management is being carried out in practice. In order to effectively manage infrastructure assets, complex consideration of various asset value factors such as budget and service as well as safety and durability are required. In this paper, we presented a theory to evaluate and quantify the road network value for efficient asset management of the road network. We also presented a method of simulation to apply the theory presented in this paper. Through simulation and the results derived from this study, it is possible to specify the budget for the future national asset management, and to optimize the strategy for the management of old road facilities.

Seismic Performance of Special Shear Wall Structural System with Effectively Reduced Reinforcement Detail (완화된 단부 배근상세를 갖는 특수전단벽 구조시스템의 내진성능평가)

  • Chun, Young-Soo;Lee, Ki-Hak;Lee, Hyo-Won;Park, Young-Eun;Song, Jin-Kyu
    • Journal of the Korea Concrete Institute
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    • v.25 no.3
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    • pp.271-281
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    • 2013
  • The current seismic design code prescribes that a structural wall should be designed as a special shear wall when the building height is more than 60 m and its seismic design category is classified as D. However, the use of a special shear wall has a negative effect on constructability and economic efficiency. In the present study, the seismic performance of a special shear wall and a special shear wall with relaxed reinforcement detail was evaluated through a cyclic reversal loading test. The specimens were constructed to measure the results of the experimental variable regarding the reinforcement details of the special boundary element. Next, the seismic performances of a special shear wall structural system and that of a special shear wall structural system with relaxed reinforcement detail was evaluated by methods proposed in the FEMA P695. The cyclic reversal loading test results of this study showed that the performance of the shear wall with relaxed reinforcement detail was almost similar to the performance of a special shear wall and has the performance which requested from standard. The results of the seismic evaluation showed that all special shear walls with relaxed reinforcement detail are satisfied with the design code and seismic performance.

마그네트론 스퍼터링에 의해 제조된 CrAlSiN 박막의 화학성분에 따른 온도저항계수와 미세구조

  • Mun, Seon-Cheol;Ha, Sang-Min;Kim, Sang-Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.100-102
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    • 2013
  • Magnetron-sputtering법을 사용하여 기존에 연구하였던 CrAlN (Cr 7:Al 3)박막에 Si를 첨가하여 Si의 함량 변화에 따라 미세구조와 화학적 결합상태, 온도저항계수(TCR) 및 산화저항의 영향과 기계적특성 개선을 통한 multi-functional heater resistor layer로써의 가능성을 연구하였다. CrAlSiN 박막의 Si 함량에 변화에 따라 온도저항계수 변화를 확인하였으며 X-선 회절 분석(XRD) 패턴 분석결과 CrAlSiN 박막의 결정구조가 Bl-NaCl 구조를 가지고 있는 것을 확인하였으며 SEM과 AFM을 통한 표면 및 미세구조 분석결과 Si의 함량이 증가할수록 입자가 조밀해짐을 알 수 있었다. 최근 digital priting technology의 핵심 기술로 부각되고 있는 inkjet priting technology는 널리 태양전지뿐만 아니라 thin film process, lithography와 같은 반도체 공정 기술에 활용 할 수 있기 때문에 반도체 제조장비에도 사용되고 있으며, 현재 thermal inkjet 방식을 사용하고 있다. Inkjet printing technology는 전기 에너지를 잉크를 배출하기 위해 열에너지로 변환하는 thermal inkjet 방식을 사용하고 있는데, 이러한 thermal inkjet 방식은 기본적으로 전기저항이 필요하지만 electrical resistor layer는 잉크를 높은 온도에서 순간적으로 가열하기 때문에 부식이나 산화 등의 문제가 발생할 수 있어 이에 대한 보호층을 필요로 한다. 하지만, 고해상도, 고속 잉크젯 프린터, 대형 인쇄 등을 요구되고 있어 저 전력 중심의 잉크젯 프린터의 열효율을 방해하는 보호층 제거에 필요성이 제기되고 있다. 본 연구는 magnetron-sputtering을 사용하여 기존의 CrAlN 박막에 Si를 합성하여 anti-oxidation, corrosion resistance 그리고 low temperature coefficient of resistance 값을 갖는 multi-functional heater resistor layer로써 CrAlSiN 박막의 Si 함량에 따른 효과에 초점을 두었다. 본 실험은 CrAlN 박막에 Si 함량을 4~11 at%까지 첨가시켜 함량의 변화에 따른 특성변화를 확인하였다. 함량이 증가할수록 amorphous silicon nitride phase의 영향으로 박막의 roughness는 감소하였으며 XRD 분석결과 (111) peak의 Intensity가 감소함을 확인하였으며 SEM 관찰시 모든 박막이 columnar structure를 나타내었으며 Si함량이 증가할수록 입자가 치밀해짐을 보여주었다.Si함량이 증가할수록 CrAlN 박막에 비하여 면저항은 증가하였으며 TCR 측정결과 Si함량이 6.5 at%일 때 가장 안정한 TCR값을 나타내었다. Multi-functional heater resistor layer 역할을 하기 위해서, CrAlSiN 박막의 원소 분포, 표면 거칠기, 미세조직, 전기적 특성 등을 조사하였다. CrAlN 박막의 Si의 첨가는 크게 XRD 분석결과 주상 성장을 억제 할 수 있으며 SEM 분석을 통하여 Si 함량이 증가할수록 Si3N4 형성이 감소하며 입자크기가 작아짐을 확인하였다. 면저항의 경우 Si 함량이 증가함에 따라 높은 면저항을 나타내었으며 Si함량이 6.5 at%일 때 가장 낮은 TCR 값인 3120.53 ppm/K값을 보였다. 이 값은 상용되고 있는 heater resistor보다 높지만, CrAlSiN 박막이 더 우수한 기계적 특성을 가지고 있기 때문에 hybrid heater resistor로 적용할 수 있을 것으로 기대된다.

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Verarbeitungsprozess der Bedeutungen von sprachlichen $Ausdr\"{u}cken$ (언어표현에 나타난 의미의 처리과정)

  • OH Young Hun
    • Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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    • v.3
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    • pp.277-301
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    • 2001
  • 우리가 간단히 사용하는 언어는 실제적으로 아주 복잡한 진행과정을 가지고 있다. 사전상의 각 어휘는 대화상황에서 상호 작용하는 초기단계의 역할을 하며, 표현은 과거나 현재에 행해지는 대화상황 및 대화참여자의 발화 과정에서 생기는 일종의 일체감을 표시한다. 의사 소통을 한다는 것은 단어나 문장에 대한 다양한 의미와 각각의 개념에서 지시되는 표현을 수단으로 발생하는 대화상의 연관성을 의미한다. 이러한 모든 것은 의사소통에 있어 의미의 다양성과 관련을 맺고있다. 우리는 표현을 통하여 매우 복잡하고 다양한 양상들을 볼 수 있다. 대화내용에 따라 똑같은 표현들이 서로 다르게 이해될 수 있기 때문이다. 언어는 단지 사람이 행하는 언어처리의 일부만을 보여줄 뿐이다 언어를 처리하는데 있어서 문제가 되는 것은 매우 복잡하고 구성적인 진행과정이다. 청자는 의사소통이 진행되는 과정에서 활자와 함께 주어진 정보를 처리함으로써 상황을 내적 형상화하게 된다. 따라서 청자는 표현의 의미를 이해하려고 노력하며, 다양한 방법을 동원한 지식을 사용한다. 의사소통에 있어서 통사적$\cdot$의미적인 지식, 문맥에 맞는 대화지식 혹은 일반 지식을 대화상황에 맞게 적용하는 것이 그 예라 할 수 있다. 지시적 언어의 표현은 사전적으로 고정된 단어의 의미를 규정하거나 또는 이와 같은 단어의 의미에 정확하고 적절한 지시사를 규정하는 근거가 된다. 인칭$\cdot$장소$\cdot$시간을 지시하는 언어 Personal-, Lokal-, Temporaldeixis는 언어 시스템을 형성하게 되는데, 활자와 청자는 이러한 표현을 인칭$\cdot$장소$\cdot$시간으로 형상화하면서 의사소통을 한다. 따라서 자연어의 처리과정에 나타나는 다양한 표현들에 대한 심리학 및 언어학의 강력한 연구가 요구된다.에 기대어 텍스트, 문장, 어휘영역 등이 투입되어 적용되었으며, 이에 상응되게 구체적인 몇몇 방안들이 제시되었다. 학습자들이 텍스트를 읽고 중심내용을 찾아내며, 단락을 구획하고 또한 체계를 파악하는데 있어서 어휘연습은 외국어 교수법 측면에서도 매우 관여적이며 시의적절한 과제라 생각된다. Sd 2) PL - Sn - pS: (1) PL[VPL - Sa] - Sn - pS (2) PL[VPL - pS] - Sn - pS (3) PL(VPL - Sa - pS) - Sn - pS 3) PL[VPL - pS) - Sn -Sa $\cdot$ 3가 동사 관용구: (1) PL[VPL - pS] - Sn - Sd - Sa (2) PL[VPL - pS] - Sn - Sa - pS (3) PL[VPL - Sa] - Sn - Sd - pS 이러한 분류가 보여주듯이, 독일어에는 1가, 2가, 3가의 관용구가 있으며, 구조 외적으로 동일한 통사적 결합가를 갖는다 하더라도 구조 내적 성분구조가 다르다는 것을 알 수 있다. 우리는 이 글이 외국어로서의 독일어를 배우는 이들에게 독일어의 관용구를 보다 올바르게 이해할 수 있는 방법론적인 토대를 제공함은 물론, (관용어) 사전에서 외국인 학습자를 고려하여 관용구를 알기 쉽게 기술하는 데 도움을 줄 수 있기를 바란다.되기 시작하면서 남황해 분지는 구조역전의 현상이 일어났으며, 동시에 발해 분지는 인리형 분지로 발달하게 되었다. 따라서, 올리고세 동안 발해 분지에서는 퇴적작용이, 남황해 분지에서는 심한 구조역전에 의한 분지변형이 동시에 일어났다 올리고세 이후 현재까지, 남황해 분지와 발해 분지들은 간헐적인 해침과 함께 광역적 침강을 유지하면서 안정된 대륙 및 대륙붕 지역으로 전이되었다.

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Gender Differences in the Effect of Alcohol Use on Intent and Lethality of Suicidal Attempts (알코올 사용이 자살시도의 심각성과 치명도에 미치는 영향-성별 차이를 중심으로)

  • Lee, Jinhee;Min, Seongho;Ahn, Joung-Sook;Park, Ki-Chang;Kim, Min-Hyuk;Kim, Heungkyu
    • Korean Journal of Psychosomatic Medicine
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    • v.24 no.2
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    • pp.236-243
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    • 2016
  • Objectives : The aim of this study was to clarify the role of alcohol use disorders and acute alcohol consumption in suicide attempts by gender. Methods : Data of 1,152 suicide attempters(487 males and 742 females) who had visited an emergency center was gathered. Suicide attempts were categorized into three groups according to alcohol use: an alcohol use disorder group(AUD), an acute alcohol use group(AAU), and a no-alcohol use group(NAU). The intent and lethality of suicide attempts were evaluated by Suicidal Intents Scale and Risk-Rescue Rating Scale. Results : For Suicidal Intents Scale score, the male AUD group revealed a significantly lower mean score than the male AAU one. However, there were no statistically significant differences for female subjects across subgroups. With regard to the Risk-Rescue Rating Scale score, there were no significant differences for males, while the AUD group showed both the lowest highest rescue scores and lowest risk-rescue scores within female groups. Conclusions : AUD in females was more likely regarding impulsive suicide attempts with high rescue chances. Consuming alcohol might have different effect on suicide attempts by gender and our study shows that alcohol use is an important risk factor according to gender, particularly with regard to female suicide attempts.

Deep learning algorithm of concrete spalling detection using focal loss and data augmentation (Focal loss와 데이터 증강 기법을 이용한 콘크리트 박락 탐지 심층 신경망 알고리즘)

  • Shim, Seungbo;Choi, Sang-Il;Kong, Suk-Min;Lee, Seong-Won
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.23 no.4
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    • pp.253-263
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    • 2021
  • Concrete structures are damaged by aging and external environmental factors. This type of damage is to appear in the form of cracks, to proceed in the form of spalling. Such concrete damage can act as the main cause of reducing the original design bearing capacity of the structure, and negatively affect the stability of the structure. If such damage continues, it may lead to a safety accident in the future, thus proper repair and reinforcement are required. To this end, an accurate and objective condition inspection of the structure must be performed, and for this inspection, a sensor technology capable of detecting damage area is required. For this reason, we propose a deep learning-based image processing algorithm that can detect spalling. To develop this, 298 spalling images were obtained, of which 253 images were used for training, and the remaining 45 images were used for testing. In addition, an improved loss function and data augmentation technique were applied to improve the detection performance. As a result, the detection performance of concrete spalling showed a mean intersection over union of 80.19%. In conclusion, we developed an algorithm to detect concrete spalling through a deep learning-based image processing technique, with an improved loss function and data augmentation technique. This technology is expected to be utilized for accurate inspection and diagnosis of structures in the future.

Southern Cone Liberalization: Experiences and Lessons (남미(南美)의 경제자유화(經濟自由化) : 경험(經驗)과 교훈(敎訓))

  • Park, Won-am
    • KDI Journal of Economic Policy
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    • v.12 no.3
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    • pp.125-151
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    • 1990
  • This paper reviews the economic liberalization experiences of the Southern Cone countries and draws some lessons from their experiences. The Southern Cone countries-Chile, Argentina and Uruguay-followed the different sequences in liberalization. Chile implemented the fiscal reform and the following comprehensive trade reform in the beginning of liberalization, but capital controls were maintained until 1979. Argentina and Uruguay placed more emphasis on the financial reform with the goods market reformed afterwards, but the fiscal sector was never reformed in Argentina. Since the serious inflation plagued the Southern Cone countries, they combined the economic liberalization scheme with the economic stabilization programmes which are based on the monetarist model. Although economic situations in the Southern Cone countries are quite different from those of Korea, we can learn many lessons from their experiences. First, the monetary and fiscal policies should consist of strict financial discipline to bring in the stable domestic inflation. Without the domestic stabilization, the financial liberalization could disturb the domestic economy as the capital inflows in particular generate a real exchange rate appreciation. Second, the monetary approach which is based on the full purchasing power parity and perfect capital mobility make stabilization as simple as a matter of the appropriate exchange rate policy and the proper rate of domestic credit creation. The unsuccessful experiences with monetarist stabilization in the Southern Cone countries suggest that the monetarist model cannot make real exchange rate and real interest rate stable with the trade and financial reform. Third, both the theory and practice have not yet provided a precise solution on the optimal sequencing and speed of the goods and financial market. Nonetheless, it seems desirable to keep the real exchange rate and the real interest rate stable by gradually opening up the current account and then the capital account.

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Mencius Thoughts on Social Welfare (맹자사상의 사회복지적 함의)

  • Kim, Young-Min
    • The Journal of Korean Philosophical History
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    • no.57
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    • pp.91-125
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    • 2018
  • This study aims at attempting to make a new interpretation of Mencius from the point of social welfare. The thoughts of social welfare, found from Mencius, are temporal and humanistic and near to those in nowadays. Social welfare began under the name of philanthropic work, relief work, charitable work or social work from the Industrial Revolution in the 18th century on. Welfare means the whole social activities such as satisfying the fundamental desires of the social members, ensuring the conditions of their lives, and ultimately achieving social integration and stability. It means the conditions of their lives and wellbeing. Wellbeing means the minimal physical desires and psychological stability. The realization of the economic system through concept of steady livelihood and steady mind, tax system and well-field system, proposed by Mencius, can be ensured by the whole social activities such as ensuring the stable lives of the social members, enriching and satisfying their happiness and ultimately achieving social integration and stability. The thoughts of Mencius include people-as-root idea, which regards people as most important and tries to solve the instability and inequality that are the structural vulnerabilities in modern capitalist society. His concept of Way of the king means promoting people's sense of happiness through education of morality, based upon the people-as-root idea and filial and fraternal responsibilities. The main ideas of social welfare include living like a human being, ensuring minimal physical and psychological stabilities through social welfare system and welfare policy, enriching human dignity and freedom and enhancing the quality of lives. The thoughts of Mencius include all the above ideas. In particular, he desired to establish ethically and morally stable society by economically implementing the well-field system in Zhou dynasty, based upon politically benevolent governance of the politicians. That society was the people-as-root society, the realization of which was the ideal society Mencius desired to establish, and the goal of his thoughts on social welfare. This study, among the thoughts of Mencius, investigated his ideas on social welfare and the practical ethics for applying them to real society. In addition, to understand his ideas on social welfare, not only the social and economic backgrounds and conditions but also the political ideas at that time were also investigated. This will provide the opportunity to make more in-depth research of the elements of social welfare intrinsically contained in his thoughts.

System Reliability-Based Design Optimization Using Performance Measure Approach (성능치 접근법을 이용한 시스템 신뢰도 기반 최적설계)

  • Kang, Soo-Chang;Koh, Hyun-Moo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.3A
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    • pp.193-200
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    • 2010
  • Structural design requires simultaneously to ensure safety by considering quantitatively uncertainties in the applied loadings, material properties and fabrication error and to maximize economical efficiency. As a solution, system reliability-based design optimization (SRBDO), which takes into consideration both uncertainties and economical efficiency, has been extensively researched and numerous attempts have been done to apply it to structural design. Contrary to conventional deterministic optimization, SRBDO involves the evaluation of component and system probabilistic constraints. However, because of the complicated algorithm for calculating component reliability indices and system reliability, excessive computational time is required when the large-scale finite element analysis is involved in evaluating the probabilistic constraints. Accordingly, an algorithm for SRBDO exhibiting improved stability and efficiency needs to be developed for the large-scale problems. In this study, a more stable and efficient SRBDO based on the performance measure approach (PMA) is developed. PMA shows good performance when it is applied to reliability-based design optimization (RBDO) which has only component probabilistic constraints. However, PMA could not be applied to SRBDO because PMA only calculates the probabilistic performance measure for limit state functions and does not evaluate the reliability indices. In order to overcome these difficulties, the decoupled algorithm is proposed where RBDO based on PMA is sequentially performed with updated target component reliability indices until the calculated system reliability index approaches the target system reliability index. Through a mathematical problem and ten-bar truss problem, the proposed method shows better convergence and efficiency than other approaches.