• 제목/요약/키워드: a new concept of stability

검색결과 167건 처리시간 0.028초

터널굴착변위를 활용한 시공중 피드백 해석기법 연구 (Feedback Analysis Technique for Tunnel Safety by Using Displacements Measured during the Tunnel Excavation)

  • 박시현;신용석
    • 한국지반공학회논문집
    • /
    • 제24권1호
    • /
    • pp.81-89
    • /
    • 2008
  • 본 연구에서는 굴착이 진행 중인 터널 시공현장에서 계측변위를 활용하여 신속하게 터널의 안정성을 정량적으로 평가할 수 있는 기법을 새롭게 개발하였다. 이를 위해, 본 연구에서는 Critical strain 개념을 새롭게 도입하였으며, 굴착중인 터널의 안정성 평가에 이를 활용하였다. 본 연구에서 개발한 해석기법은, 굴착면에서의 변위값을 입력하여 주변지반의 변형률을 구하는 방법으로서, 기존에 제안된 해석기법을 재검토하여, 상대변위활용기법, 숏크리트 반영기법, 지반의 이방특성 반영기법을 새롭게 제안하였다. 아울러 본 연구에서 제안한 해석기법을 토대로 해석모듈을 개발하였으며, 개발된 해석모듈의 활용성을 평가하기 위한 검증을 수행하였다. 검증 방법으로는 먼저, 이론해석과 상용프로그램(Pentagon-3D, Flac-2D) 해석을 통해 원형 터널에서의 굴착변위를 서로 비교하여, 상용프로그램의 활용성을 검토하였다. 이어서, 두 종류의 상용프로그램을 활용하여 숏크리트 라이닝의 유무에 따라, 동일한 초기조건에서의 굴착변위를 구하여, 두 상용프로그램의 해석결과를 비교하였다. 마지막으로, 상용프로그램에서 획득한 터널굴착변위를 본 연구에서 개발한 해석모듈(FAST-Ver. 1.2, Feedback Analysis System for Tunneling)에 입력치로 이용하여, 원지반의 하중상태 및 재료특성 등을 추정하고, 추정된 값들이 당초 가정하였던 값들을 얼마만큼 재현할 수 있는지에 대한 검증을 수행하였다.

GNSS를 활용한 초장대 현수교의 거동 특성 분석 (Behavior Character Analysis of Super Long Suspension Bridge using GNSS)

  • 박제성;홍승환;김미경;김태훈;손홍규
    • 대한원격탐사학회지
    • /
    • 제35권5_2호
    • /
    • pp.831-840
    • /
    • 2019
  • 최근 장대교량의 경간장이 길어지면서 주탑간 거리(span)가 기존의 한계를 넘는 교량에 대해 초장대교량이라는 개념이 새롭게 제시되었다. 또한 장대교량의 구조가 복잡해지고, 안전성이 중요해지면서 시공 중 계측의 필요성이 더욱 커졌다. 하지만 장대교량에 기존 계측센서를 지속적으로 적용하는 데는 한계가 있다. 이에 기존 계측센서들의 한계를 보완하고자 위성항법시스템(GNSS: Global Navigation Satellite System)을 활용하기 위한 연구가 진행되고 있다. 본 연구는 최종적으로 2축경사계, 변형률계, 풍향풍속계와 GNSS를 혼용하여 초장대현수교의 거동 특성을 파악하고, 세부 모니터링 방법을 제시하고자 하였다. 이를 위해 GNSS를 이용하여 주탑의 절대좌표와 교축진행방향을 산출하였고, 장기거동을 분석하여 시공 직후 주탑의 영구 변위와 안정화 여부를 평가하였다. 또한 풍향이 대상교량의 거동에 미치는 영향을 수치적으로 나타냈으며, 이를 통해 대상교량의 거동특성을 분석하였다. 본 연구 결과, GNSS를 활용한 교량 계측은 분석 목적에 따라 데이터 처리가 용이한 것으로 나타났다. 또한, 초장대교량의 유지관리에 있어 기존의 계측센서와 GNSS을 활용한다면 각 계측 데이터의 오차 파악 및 보정을 통한 모니터링 시스템의 개선과 정확한 변위관측, 그리고 거동특성을 함께 파악하는 효과적인 모니터링 시스템을 구축 할 수 있다는 점을 확인할 수 있었다.

맹자사상의 사회복지적 함의 (Mencius Thoughts on Social Welfare)

  • 김영민
    • 한국철학논집
    • /
    • 제57호
    • /
    • pp.91-125
    • /
    • 2018
  • 본 논문은 사회복지 관점에서 바라 본 맹자에 대한 새로운 해석이다. 맹자에게서 찾아볼 수 있는 사회복지 사상은 현세적이고 인본주의적으로 이는 지금의 사회복지 이념에 근접해 있다. 사회복지는 18세기 산업혁명 이전부터 박애사업, 구제사업, 자선사업 혹은 사회사업 등의 이름으로 시작되었다. 복지란 사회 구성원의 기본적 욕구를 충족시키고 삶의 조건을 보장하는 것으로 궁극적으로는 사회 통합과 안녕을 달성하려는 사회적 활동의 총체를 뜻하기도 한다. 이는 사회구성원의 생활하는 삶의 상태이며 안정(Well bing)을 의미한다. 안정은 최소한의 물질적 욕구와 심리적 안정을 말한다. 맹자의 항산 항심론과 공정한 조세 제도, 정전제를 통한 경제제도의 실현은 사회복지 이념인 사회구성원의 안정적인 삶을 보장하고 행복을 증진 충족시키며, 궁극적으로는 사회 통합과 안녕을 달성하려는 사회적 활동의 총체와 뜻을 같이 한다. 맹자의 사상에는 백성을 중시한 민본사상이 내재해 있으며, 현대 자본주의 사회가 구조적으로 안고 있는 불안과 불평등의 문제를 왕도정치에서 적극적으로 해결하고자 했다. 맹자의 왕도정치는 물질적 안정을 기반으로 한 민본사상과 효제를 근본으로 하여 도덕성의 교육으로 백성들의 행복감을 증진시킬 수 있다는 것이다. 인간이 인간다운 생활을 영위하고 최소한의 물질적 안정과 심리적 안정을 사회복지제도와 복지정책의 주요 요소로 하여 최저생활 보장, 사회적 평등, 인간의 존엄성과 자유의 확대 및 생활의 질 향상 등이 사회복지의 주요 이념이다. 맹자의 사상 안에는 이와 같은 사회복지의 주요 이념이 모두 포괄되어 있다. 특히 맹자는 정치적으로는 위정자의 인정을 바탕으로 하고, 경제적으로는 주나라의 정전제를 시행하여, 윤리 도덕적으로 안정된 사회가 확립되기를 원했다. 그 사회는 바로 백성을 근본으로 하는 사회이며, 그러한 사회의 실현이 맹자가 원했던 이상사회였고, 맹자 사회복지사상의 목표라고 할 수 있을 것이다. 본 논문은 맹자의 사상 속에서 오늘날의 시대적 요구에 부응할 수 있는 사회복지 이념과 이를 현실에 적용할 수 있는 실천윤리로서의 규정을 살펴보았다. 또한 맹자의 사회복지 사상을 이해하기 위해 당시의 사회적 배경과 경제적 상황, 정치적 관념에 대해 고찰하였다. 이는 맹자의 사상 속에 본질적으로 내재되어 있는 사회복지적 요소를 심층적으로 고찰하는 계기가 될 것으로 판단된다.

인수합병(M&A) 이후 HR 활용: D사의 사례를 중심으로 (A Study on between Human Resource Management and Merger and Acquisition: The case of D company)

  • 김형호;한정희
    • 산업융합연구
    • /
    • 제13권4호
    • /
    • pp.11-28
    • /
    • 2015
  • A company have to grow constantly. If a company does not grow and stagnant, it will be finally out of the market. The contemporary companies fully make use of M&A to search for new growth engines. The reason of companies using M&A as a important tool of a business strategy is the fastest way to achieve technology power, market power, competitiveness. The form of M&A was that leading companies take over smaller companies or merger and acquisition between small companies in the middle of 2000. But now, Mega mergers between industry leading companies often occur and especially domestic of course M&A of foreign companies occurs actively. These days the boom of stock market and the big companies are pouring on sale by restructuring, privatization and the basis of low interest will make the M&A market continuously. In this study, I suggest a solution of actual human resources management by analyzing proven M&A cases and search for various problems of a gap in the leadership and communication in connection with integration of organization culture after M&A. First of all, I arrange the theoretical concept of the subject and analyze the key factors of the success M&A cases, lastly I suggested a HR strategy after M&A. After M&A, HR strategy is ; First, a company have to build a organization culture which is that merger company accommodate a excellent organizational characteristic of predecessor company with consideration of culture difference. Second, M&A must proceed to remove of anxiety about the future and employment stability by excellent leaderships. Third, organization integration after M&A is influenced by the level of integration for that reason it was verified that M&A have to make progress by communication of each 2 organizations.

  • PDF

경제성분석 프로그램을 이용한 도심형 마이크로그리드 최적 설계 (Optimal Design of Urban MICROGRID using Economical Analysis Program)

  • 유승덕;임성우;임유석;황성욱;이학주
    • KEPCO Journal on Electric Power and Energy
    • /
    • 제8권2호
    • /
    • pp.69-72
    • /
    • 2022
  • This paper actually investigates the load on major large-scale buildings in the downtown area, examines the economic feasibility of installing PV and ESS in a microgrid target building, and evaluates whether an electric vehicle capable of V2G through two buildings is effective as an economical analysis program (HOMER) was analyzed using. It is economical to install a mixture of ESS rather than using the whole PV, and it is shown that if there is an electric vehicle using the V2G function of EV, there is an economic effect to replace the PV. So that Incentives and policies are needed to replace a large area of PV and utilize the existing parking lot to lead EV as a resource of the microgrid. Currently, P2X technology that stores power as ESS or converts it to other energy to control when surplus renewable energy occurs in large-capacity solar power plants and wind farms, etc. This is being applied, and efforts are being made to maintain the stability of the system through the management of surplus power, such as replacing thermal energy through a heat pump. Due to the increase in electric vehicles, which were recognized only as a means of transportation, technologies for using electric vehicles are developing. Accordingly, existing gas stations do not only supply traditional chemical fuels, but electricity, and super stations that also produce electricity have appeared. Super Station is a new concept power plant that can produce and store electricity using solar power, ESS, V2G, and P2G. To take advantage of this, research on an urban microgrid that forms an independent system by tying a large building and several buildings together and supplies power through a super station around the microgrid is in full swing.

Smart City Energy Inclusion, Towards Becoming a Better Place to Live

  • Cha, Sang-Ryong
    • World Technopolis Review
    • /
    • 제8권1호
    • /
    • pp.59-70
    • /
    • 2019
  • Where is a better place to live? In the coming era, this should be more than simply a livable place. It should be an adaptable place that has a flexible system adaptable to any new situation in terms of diversity. Customization and real-time operation are needed in order to realize this technologically. We expect a smart city to have a flexible system that applies technologies of self-monitoring and self-response, thereby being a promising city model towards being a better place to live. Energy demand and supply is a crucial issue concerning our expectations for the flexible system of a smart city because it is indispensable to comfortable living, especially city living. Although it may seem that energy diversification, such as the energy mix of a country, is a matter of overriding concern, the central point is the scale of place to build grids for realizing sustainable urban energy systems. A traditional hard energy path supported by huge centralized energy systems based on fossil and nuclear fuels on a national scale has already faced difficult problems, particularly in terms of energy flexibility/resilience. On the other hand, an alternative soft energy path consisting of small diversified energy systems based on renewable energy sources on a local scale has limitations regarding stability, variability, and supply potential despite the relatively light economic/technological burden that must be assumed to realize it. As another alternative, we can adopt a holonic path incorporating an alternative soft energy path with a traditional hard energy path complimentarily based on load management. This has a high affinity with the flexible system of a smart city. At a system level, the purpose of all of the paths mentioned above is not energy itself but the service it provides. If the expected energy service is fixed, the conclusive factor in choosing a more appropriate system is accessibility to the energy service. Accessibility refers to reliability and affordability; the former encompasses the level of energy self-sufficiency, and the latter encompasses the extent of energy saving. From this point of view, it seems that the small diversified energy systems of a soft energy path have a clear advantage over the huge centralized energy systems of a hard energy path. However, some insuperable limitations still remain, so it is reasonable to consider both energy systems continuing to coexist in a multiplexing energy system employing a holonic path to create and maintain reliable and affordable access to energy services that cover households'/enterprises' basic energy needs. If this is embodied in a smart city concept, this is nothing else but smart energy inclusion. In Japan, following the Fukushima nuclear accident in 2011, a trend towards small diversified energy systems of a soft energy path intensified in order to realize a nuclear-free society. As a result, the Government of Japan proclaimed in its Fifth Strategic Energy Plan that renewable energy must be the main source of power in Japan by 2050. Accordingly, Sony vowed that all the energy it uses would come from renewable sources by 2040. In this situation, it is expected that smart energy inclusion will be achieved by the Japanese version of a smart grid based on the concept of a minimum cost scheme and demand response.

전통풍수의 상징적 의미를 체용(體用)한 간판 배색 제안 - 사업주의 본명궁을 중심으로 - (Proposed Color Scheme with Feng Shui Significance - Focused on the Bonmyeonggung of business owners -)

  • 박효철;이승노
    • 한국실내디자인학회논문집
    • /
    • 제22권2호
    • /
    • pp.131-139
    • /
    • 2013
  • The purpose of this study is to propose a new direction for color schemes of city signages to provide psychological stability to business owners and improve business value. Types of city sign color schemes and Feng Shui awareness of business owners were examined. Color schemes for signs were proposed, reflecting city landscape colors, color perception theory, and the Feng Shui Sangsaeng Sanggeuk theory. Results of the study can be summarized as follows. First, in order to secure colorscape quality of existing city buildings, signs should be small and consist of only three or fewer colors. Second, existing signage colors and the Feng Shui ideas of business owners have something in common with the five traditional cardinal colors. Thus, it can be interpreted that Feng Shui ideas are deeply rooted in the color use awareness of the Korean people. Third, background colors of signages can reflect the idea of innate Sangsaeng according to the Bonmyeonggung of business owners. The concept of acquired Sanggeuk can also be applied to other design elements such as characters. Fourth, as a second choice according to the function of sign, city landscape or preference of business owner, etc., the background color can remain a color of Sangsaeng, while other design elements such as characters can use a color scheme corresponding to Bihwasaek. Fifth, signs can create a statement and stand out using lightness contrast or saturation contrast theories. A variety of sign color schemes are also possible just by altering the lightness and saturation levels.

수요와 공급의 불확실성을 고려한 시간대별 순동예비력 산정 방안 (Dynamic Reserve Estimating Method with Consideration of Uncertainties in Supply and Demand)

  • 권경빈;박현곤;류재근;김유창;박종근
    • 전기학회논문지
    • /
    • 제62권11호
    • /
    • pp.1495-1504
    • /
    • 2013
  • Renewable energy integration and increased system complexities make system operator maintain supply and demand balance harder than before. To keep the grid frequency in a stable range, an appropriate spinning reserve margin should be procured with consideration of ever-changing system situation, such as demand, wind power output and generator failure. This paper propose a novel concept of dynamic reserve, which arrange different spinning reserve margin depending on time. To investigate the effectiveness of the proposed dynamic reserve, we developed a new short-term reliability criterion that estimates the probability of a spinning reserve shortage events, thus indicating grid frequency stability. Uncertainties of demand forecast error, wind generation forecast error and generator failure have been modeled in probabilistic terms, and the proposed spinning reserve has been applied to generation scheduling. This approach has been tested on the modified IEEE 118-bus system with a wind farm. The results show that the required spinning reserve margin changes depending on the system situation of demand, wind generation and generator failure. Moreover the proposed approach could be utilized even in case of system configuration change, such as wind generation extension.

Application and optimal design of the bionic guide vane to improve the safety serve performances of the reactor coolant pump

  • Liu, Haoran;Wang, Xiaofang;Lu, Yeming;Yan, Yongqi;Zhao, Wei;Wu, Xiaocui;Zhang, Zhigang
    • Nuclear Engineering and Technology
    • /
    • 제54권7호
    • /
    • pp.2491-2509
    • /
    • 2022
  • As an important device in the nuclear island, the nuclear coolant pump can continuously provide power for medium circulation. The vane is one of the stationary parts in the nuclear coolant pump, which is installed between the impeller and the casing. The shape of the vane plays a significant role in the pump's overall performance and stability which are the important indicators during the safety serve process. Hence, the bionic concept is firstly applied into the design process of the vane to improve the performance of the nuclear coolant pump. Taking the scaled high-performance hydraulic model (on a scale of 1:2.5) of the coolant pump as the reference, a united bionic design approach is proposed for the unique structure of the guide vane of the nuclear coolant pump. Then, a new optimization design platform is established to output the optimal bionic vane. Finally, the comparative results and the corresponding mechanism are analyzed. The conclusions can be gotten as: (1) four parameters are introduced to configure the shape of the bionic blade, the significance of each parameter is herein demonstrated; (2) the optimal bionic vane is successfully obtained by the optimization design platform, the efficiency performance and the head performance of which can be improved by 1.6% and 1.27% respectively; (3) when compared to the original vane, the optimized bionic vane can improve the inner flow characteristics, namely, it can reduce the flow loss and decrease the pressure pulsation amplitude; (4) through the mechanism analysis, it can be found out that the bionic structure can induce the spanwise velocity and the vortices, which can reduce drag and suppress the boundary layer separation.

Ant-Q 학습을 이용한 Gale-Shapley 문제 해결에 관한 연구 (Solving the Gale-Shapley Problem by Ant-Q learning)

  • 김현;정태충
    • 정보처리학회논문지B
    • /
    • 제18B권3호
    • /
    • pp.165-172
    • /
    • 2011
  • 본 논문에서는 생물학의 개미들이 학습을 통해 목표를 획득하는 방법을 응용한 Ant-Q 알고리즘(Ant Q learning System)[1]을 Gale-Shapley[2]알고리즘을 통해 제시되었던 안정된 결혼문제(SMP: Stable Marriage Problem)[3]의 새로운 해법을 찾기 위해 적용 하였다. SMP는 남성($m_i$)들과 여성($w_j$)들은 각자 자신이 좋아하는 이상형에 대한 선호도(PL: preference list)를 바탕으로 안정이면서도 최선의 짝을 찾는 것을 목표로 하고 있다. Gale-Shapley 알고리즘은 남성(혹은 여성) 위주로 안정적(stability)인 짝(Matching)을 성사시키므로 다양한 조건을 수용하지 못한다. 본 논문에 적용된 Ant-Q는 개미(Ant)의 페로몬을 활용한 학습인 ACS(Ant colony system)에 강화학습의 일종인 Q-학습[9]을 추가한 방법으로, SMP의 새로운 해법을 찾을 수 있었다.