• Title/Summary/Keyword: Singular System

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A Study on the Application of River Surveying by Airborne LiDAR (항공라이다의 하천측량 적용 방안 연구)

  • Choi, Byoung Gil;Na, Young Woo;Choo, Ki Hwan;Lee, Jung Il
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.2
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    • pp.25-32
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    • 2014
  • The river plan executes the role for prevention of disaster and protection of environment, and requires the surveying results with high accuracies for managing river, dam, reservoir which will be the major infrastructures. The purpose of this study is for comparing and analyzing the results of river surveying which is used widely for disaster management and construction industry support. The results are gathered by using LiDAR which is being used in Korea recently and by using Total station. Study area is chosen at upper area of Bukhan River which is located at Gangwon-do. Total 2 cross-sections of the two methods are extracted from the study area. The standard deviation of land part is about 0.017m which shows little difference between two methods, but the Airborne LiDAR results cannot survey the heights of the points accurately at the singular points with vertical structure and water body part. To overcome the problems through this study, there should be ways to survey the bottom river through transmission of water level within the same margin scope as land part and to survey detailed facilities used by laser exactly through continuous research and experiment. When implementation stage comes, this study expect that this document will be utilized variously for making decision in the area of planning and drawing of business and engineering not just for river regarding the major area or the area that people cannot access.

Vibration Analysis of Large Structures by the Component-Mode Synthesis (부분구조진동형 합성방법에 의한 대형구조계의 진동해석)

  • B.H. Kim;T.Y. Chung;K.C. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.30 no.3
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    • pp.116-126
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    • 1993
  • The finite element method(FEM) has been commonly used for structural dynamic analysis. However, the direct global application of FEM to large complex structures such as ships and offshore structures requires considerable computational efforts, and remarkably more in structural dynamic optimization problems. Adoption of the component-mode synthesis method is an efficient means to overcome the above difficulty. Among three classes of the component-mode synthesis method, the free-interface mode method is recognized to have the advantages of better computational efficiency and easier implementation of substructures' experimental results, but the disadvantage of lower accuracy in analytical results. In this paper, an advanced method to improve the accuracy in the application of the free-interface mode method for the vibration analysis of large complex structures is presented. In order to compensate the truncation effect of the higher modes of substructures in the synthesis process, both residual inertia and stiffness effects are taken into account and a frequency shifting technique is introduced in the formulation of the residual compliance of substructures. The introduction of the frequency shrift ins not only excludes cumbersome manipulation of singular matrices for semi-definite substructural systems but gives more accurate results around the specified shifting frequency. Numerical examples of typical structural models including a ship-like two dimensional finite element model show that the analysis results based on the presented method are well competitive in accuracy with those obtained by the direst global FEM analysis for the frequencies which are lower than the highest one employed in the synthesis with remarkably higher computational efficiency and that the presented method is more efficient and accurate than the fixed-interface mode method.

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Analysis of Interface Problem using the MLS Difference Method with Interface Condition Embedment (계면경계조건이 매입된 이동최소제곱 차분법을 이용한 계면경계문제 해석)

  • Yoon, Young-Cheol
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.4
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    • pp.215-222
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    • 2019
  • The heat conduction problem with discontinuous material coefficients generally consists of the conservative equation, boundary condition, and interface condition, which should be additionally satisfied in the solution procedure. This feature often makes the development of new numerical schemes difficult as it induces a layered singularity in the solution fields; thus, a special approximation is required to capture the singular behavior. In addition to the approximation, the construction of a total system of equations is challenging. In this study, a wedge function is devised for enriching the approximation, and the interface condition itself is embedded in the moving least squares(MLS) derivative approximation to consistently satisfy the interface condition. The heat conduction problem is then discretized in a strong form using the developed derivative approximation, which is named as the interface immersed MLS difference method. This method is able to efficiently provide a numerical solution for such interface problems avoiding both numerical quadrature as well as extra difference equations related to the interface condition enforcement. Numerical experiments proved that the developed numerical method was highly accurate and computationally efficient at solving the heat conduction problem with interfacial jump as well as the problem with a geometrically induced interfacial singularity.

Development of a Storage Level and Capacity Monitoring and Forecasting Techniques in Yongdam Dam Basin Using High Resolution Satellite Image (고해상도 위성자료를 이용한 용담댐 유역 저수위/저수량 모니터링 및 예측 기술 개발)

  • Yoon, Sunkwon;Lee, Seongkyu;Park, Kyungwon;Jang, Sangmin;Rhee, Jinyung
    • Korean Journal of Remote Sensing
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    • v.34 no.6_1
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    • pp.1041-1053
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    • 2018
  • In this study, a real-time storage level and capacity monitoring and forecasting system for Yongdam Dam watershed was developed using high resolution satellite image. The drought indices such as Standardized Precipitation Index (SPI) from satellite data were used for storage level monitoring in case of drought. Moreover, to predict storage volume we used a statistical method based on Principle Component Analysis (PCA) of Singular Spectrum Analysis (SSA). According to this study, correlation coefficient between storage level and SPI (3) was highly calculated with CC=0.78, and the monitoring and predictability of storage level was diagnosed using the drought index calculated from satellite data. As a result of analysis of principal component analysis by SSA, correlation between SPI (3) and each Reconstructed Components (RCs) data were highly correlated with CC=0.87 to 0.99. And also, the correlations of RC data with Normalized Water Surface Level (N-W.S.L.) were confirmed that has highly correlated with CC=0.83 to 0.97. In terms of high resolution satellite image we developed a water detection algorithm by applying an exponential method to monitor the change of storage level by using Multi-Spectral Instrument (MSI) sensor of Sentinel-2 satellite. The materials of satellite image for water surface area detection in Yongdam dam watershed was considered from 2016 to 2018, respectively. Based on this, we proposed the possibility of real-time drought monitoring system using high resolution water surface area detection by Sentinel-2 satellite image. The results of this study can be applied to estimate of the reservoir volume calculated from various satellite observations, which can be used for monitoring and estimating hydrological droughts in an unmeasured area.

Policy Study on Korean Retail Micro Business (국제 비교를 통한 소매업 소상공인 현황과 정책적 시사점)

  • Suh, Yong Gu;Kim, Suk Kyung
    • Journal of Distribution Research
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    • v.17 no.5
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    • pp.39-57
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    • 2012
  • The unabated influx of micro businesses has turned the Korean retailing market to a rat race, which causes severe financial distress for micro business owners due to heavy competition. The woes of these micro business owner's are exacerbated by the presence of large scale distributors such as Super Supermarket(SSM) and large discount stores. In summary, the Korean retail market is overburdened an uneconomically viable. Retailing has low barriers to entry which attracts unskilled labor or those with little capital. These start-ups have low opportunity costs since they would make low wages elsewhere in the economy. Thus, these owners are content with relatively low returns on their investment. These 'subsistence ventures' are maintained for economical viability rather than economic growth. These 'subsistence ventures' intensifies competition among small-scale businesses. The presence of large retail corporations also aggravates the situation. The recent stagnation of the economy has worsened the retail market in Korea. The overwhelming competition solidifies the coarse structural system and the prolonged economic sluggishness has increased the risk of insolvency for micro business owners. As the economy continues to stagnate, the imminent risk in retailing market will rise up to surface threatening economic stability. More systematic inflows and outflows of retailers are required in order to redress this structural problem. It has been empirically shown that the self-employment rate is high in Korea compared to other OECD countries. To draw the comparison of self-employment rate by industry, Korea shows high rates among transportation, whole sale, retail, education, lodging, and restaurants. In the case of the transportation and education service sectors, this high rate can be explained by the idiosyncratic nature of Korean culture. In the transportation sector, political policies favor private cap service and private freight carriers. In the education service sector, Koreans put particular emphasis on education that leads to many private institutions that outnumber other OECD countries. For these singular reasons, Korea maintains high micro business, self-employed rates particularly in retailing. A comparable nation is Japan, with its similar social, economic, cultural environment among OECD countries. Unlike Korea, Japan has much lower rates of micro business which continues to decrease. Also Korean retailers are much more destitute than Japanese. The fundamental problem of Korean retailing is the involuntary exit of these 'subsistence ventures,' micro businesses with low margins, in which a small drop in demand can lead to financial difficulties for the owner. This problem will be exacerbated when Korean babyboomers retire and join the micro business ventures. The first priority in order to cope with the severity of oversupply in retailing is to provide better opportunities for the potential self-employers. There should be viable alternatives to subsistent ventures. Strengthening the retirement program, scrutiny of exit process, reconfiguration of policy funds are the recommendations.

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A Study on Repetition and Multiplicite of Superhero Comics (슈퍼히어로 코믹의 반복과 다양체적 형식에 관한 연구)

  • Park, Seh-Hyuck
    • Cartoon and Animation Studies
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    • s.28
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    • pp.27-53
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    • 2012
  • American superhero comics are being produced in numerous different forms for multiple, and cross-platform media. In cinema, films based on superhero comics top the list of all time box office records. The same phenomenon of the 'Invasion of Superhero' is duplicated in Korean box office 2012, however, the korean fans are not familiar with the superheroes from the publication which provides the original source of characters and stories for other superhero related media products. Based on observing the multiple and vastness of world building characteristics of superhero comic, this paper attempts to associate the continuous creative nature and the infinite repetition of superheroes and comic texts with the identity of superhero on ontological level. First, chapter 2 examines how one superhero exists in multiple and different worlds individually by utilizing the concept of 'multi-universe' or 'multiverse' in comic texts. Initially, duplicating a superhero on multiple settings and series destroyed continuity and allowed contradiction and paradox confused narrative as a whole, but it also gave chances for comics to be more vibrant and experimental with their stories and characters. Chapter 3 analyzes the superhero comic texts in the light of repetition, concept developed by french philosopher Gilles Deleuze, and make the argument that the superheroes and texts are not repeated to generate surplus of source for economic utilitarian purposes, but it is, first and foremost, a repetition of creativeness and capability. Many concepts introduced by Deleuze in his early masterpiece, $\acute{e}$rence et R$\acute{e}$p$\acute{e}$tition> are taken to support this argument. Mainly, his critical views on generality of the identity and his effort to replace the Plato's system of representation with vibrant creative, and renewal energy of r$\acute{e}$p$\acute{e}$tition. According to Deleuze, repetition is similar concept, if not identical, to what Nietzsche called the 'eternal return' which allows the return of the Overhuman or the Superhuman, and he extends his idea that the returning Overhuman is the singular simulacre which opposes the generalization of identity, in the likes of Plato's Idea. Thus, the superhero's identity is ever changing, ever returning, and ever renewing Overhuman. The superhero must be repeated to fully actualize his/her existence. Also, based on Deleuze's reading of Bergson's texts on the Virtual, the superhero, for example Superman, is actualization of his/her multiplisit$\acute{e}$, the internally multiple, and differentiated variations from itself. These every Supermans' multiplisit$\acute{e}$ shares common memory, past, and duration, thus the Virtual of Superman. Superman becomes himself only by actualizing the movement and differentiation from these multiplisit$\acute{e}$ in his virtual on the surface of reality. On chapter 4, a popular Korean comic book character Oh, Hae-Sung's r$\acute{e}$p$\acute{e}$tition and multiplist$\acute{e}$ are analyzed, and makes comparison to that of Superman to distinguish the repetition from r$\acute{e}$p$\acute{e}$tition, and multiplicit$\acute{e}$ from diversity.

Connection of Dongmu Lee Je-ma's Sa-Sang Theory & Ken Wilber's all-quadrant approach (동무 이제마의 사상설(四象說)과 캔 윌버의 사상한(四象限) 일고(一考))

  • Heo, Hoon
    • Journal of Korean Philosophical Society
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    • v.116
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    • pp.411-435
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    • 2010
  • Ken Wilber(1949~) tries to approach integration of philosophy, emphasising the advent of the perennial philosophy in the exchange of scholarships at the present day. He suggests All Quadrant(四象限) for the first step to reach his integrated approach. In addition, his approach concretizes for AQAL(All Quadrant, All Level). His AQAL approach which can be divide into inside/outside, singular/plural, or interobjectivity/intersubjectivity is applied to a lot of fileds such as ecology, management, criminology, medical treatment and its boundary is getting bigger. The merits of Quadrant is that it can solve the problem of the plain(平原), which resolves the strength of subjective interior(cultural contexts) into the external existence(social system). From view of Dongmu Lee Je-ma(1837~1900), a former philosopher, Sa-Sang theory['Affairs-Mind-body-Objects(事心身物)', 'Heaven-Human-nature-Order(天人性命)] is in accord with Wilber in content. In Dongmu's writing, Quadrant(Affairs-Mind-body-Objects') called Sa-Sang theory(四象學) or Sasang Constitional Medicine(四象醫學) is basic component in order to explain the structure of all nature. 'Heaven-Human-nature-Order'; That is, 'Affairs-Mind-body-Objects' results in 'Heaven-Human-nature-Order' focused on human being(human body) in the universe. In other words, Sa-Sang theory is the same as the Wilver's inclusive perspectives from the universe and human being. Dongmu's Sa-Sang theory is compared with C. G. Jung(1875~1961)'s psychology and it helps both fields confirm the foundation and extend the province of application. Comparision of Dongmu's Quadrant with Wilber's is not just analogical reasoning. In comparison, Dongmu's Sa-Sang theory is more delicated and crystallized than Wilber's in medical prospective. Dongmu regards Quadrant not as diseases, but as origin of Physiology and Pathology. And he explains all of their courses as Quadrant.

The Structural Relationship between Entrepreneurial Competency, Entrepreneurial Opportunity Recognition on and Entrepreneurial Intentions of Middle-aged Eldery Office Workers (중·장년 직장인의 창업역량과 창업기회인식 및 창업의지의 구조적 관계)

  • Choi, In Woo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.5
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    • pp.169-185
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    • 2022
  • This study analyzed the effect of entrepreneurial competency on entrepreneurial intentions by using the entrepreneurial opportunity recognition as a mediator for middle and middle-aged office workers. The sub-variables of entrepreneurial competency are classified into management competency, technology competency, business competency and funding competency. 222 copies of questionnaires collected from middle-aged and elderly office workers residing across the country centered on the metropolitan area were used for empirical analysis. Based on a simple mediating model with singular mediator using SPSS v22.0 and PROCESS macro v4.0. was analyzed. As a result of the analysis, first, among entrepreneurial competencies, business competency and funding capacity were found to have a positive (+) significant effect on the entrepreneurial intentions, but management and technical competency did not have a significant effect. The higher the business competency and funding competency. Second, it was found that all of the sub-variables of entrepreneurial competency had a significant effect in the positive (+) direction on the recognition of entrepreneurial opportunities. It was confirmed that management competency has the greatest influence on the entrepreneurial opportunity recognition and technology competence has the smallest effect. Third, it was found that the entrepreneurial opportunity recognition had a significant effect on entrepreneurial intentions. The discovery of an opportunity recognizing opportunities for start-up is a prerequisite for entrepreneur. Fourth, it was found that the entrepreneurial opportunity recognition mediates between the management competency, technological competency, business competency, funding competency, and entrepreneurial intention. It suggests that opportunity discovery by recognizing opportunities for entrepreneurship is a prerequisite for start-up. As implications of this study, it suggests that in order to inspire middle-aged and elderly office workers to start their own business, it is necessary to have indirect experience with education and to establish and promote a government support system for financing.. Second, It suggests that education on leadership and organizational management is particularly necessary to strengthen the opportunity recognition. Third, it suggests that the discovery of opportunities to recognize opportunities for start-up is a prerequisite for entrepreneur. Therefore, it is necessary to prepare a manual and conduct training on opportunity search, recognition, evaluation, and utilization according to the stage of opportunity development. Fourth, it suggests that in order to strengthen the intention to start a business, ALso, it is necessary to manage both the entrepreneurial competency and entrepreneurial opportunities recognition at the same time. By presenting the practical directions that can be given differentially, we intend to contribute to the provision of practical directions and policy establishment for the promotion of entrepreneurial activities of office workers who can give vitality to the ecosystem.