• Title/Summary/Keyword: Modeling step

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The South Sea Circulation of Korea: Two-dimensional Barotrophic Model (한국 남해의 해수순환: 2차원 순압모델)

  • Chang, Kyung-Il;Park, Kyeong;Suk, Moon-Sik;Kim, Choong-Ki
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.5 no.4
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    • pp.257-266
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    • 2000
  • A vertically-averaged, two-dimensional version of the Princeton Ocean Model has been applied to the South Sea to simulate the circulation driven by tides and inflows/outflows across open boundaries. To incorporate both forcing properly, a two-step modeling approach is adopted, in which the tidal circulation is first simulated by specifying the tides along the open boundaries, and then both the calculated tidal currents and the observed steady mean currents are prescribed across the open boundaries. Model results show that the steady, subtidal circulation of the South Sea is different from the residual circulation due to tidal rectification, and subtidal currents become locally as strong as tidal currents. The Cheju Current entering the model domain across the Cheju Strait flows eastward in general while shifting onshore or offshore areas following local isobaths. The Tsushima Current entering across the southern boundary reaches farther to the north in the eastern vicinity of Cheju-Do as compared to that entering across other parts of the southern boundary. The Tsushima Current turns to the east, merges with the Cheju Current, and both the Cheju and Tsushima Current exit to the East Sea through the western channel of the Korea Strait. An intensification of the outflow occurs over the deep trough adjacent to the Tsushima Island, which appears to be due to the formation of the frictional boundary layer in order to remove excess positive relative vorticity generated by an increase in the layer thickness. The circulation driven by both the tidal and inflows/outflows is different from that driven by each forcing separately in coastal areas, which implies that both forcings should be considered simultaneously in the simulation of more realistic coastal circulation.

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Synthetic Study on the Geological and Hydrogeological Model around KURT (KURT 주변 지역의 지질모델-수리지질모델 통합 연구)

  • Park, Kyung-Woo;Kim, Kyung-Su;Koh, Yong-Kwon;Choi, Jong-Won
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.9 no.1
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    • pp.13-21
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    • 2011
  • To characterize the site specific properties of a study area for high-level radioactive waste disposal research in KAERI, the several geological investigations such as surface geological surveys and borehole drillings were carried out since 1997. Especially, KURT (KAERI Underground Research Tunnel) was constructed to understand the further study of geological environments in 2006. As a result, the first geological model of a study area was constructed by using the results of geological investigation. The objective of this research is to construct a hydrogeological model around KURT area on the basis of the geological model. Hydrogeological data which were obtained from in-situ hydraulic tests in the 9 boreholes were estimated to accomplish the objective. And, the hydrogeological properties of the 4 geological elements in the geological model, which were the subsurface weathering zone, the log angle fracture zone, the fracture zones and the bedrock were suggested. The hydrogeological model suggested in this study will be used as input parameters to carry out the groundwater flow modeling as a next step of the site characterization around KURT area.

The Impact of Entrepreneurial Temperament and Social Capital on Entrepreneurial Intention before Start-up (창업 전 기업가기질과 사회적 자본이 창업의도에 미치는 영향)

  • Yoon, Ki-Chang;Lee, Jae-Eun
    • The Journal of Industrial Distribution & Business
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    • v.8 no.6
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    • pp.97-109
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    • 2017
  • Purpose - This study aimed to investigate the effect of entrepreneurial temperament (ET) such as innovativeness, risk-taking, and proactiveness in entrepreneur's lifetime before start-up and the effect of social capital (SC) such as network ties and trustworthiness on entrepreneurial intention. Research design, data, and methodology - We examined the components of ET (innovativeness, risk-taking, and proactiveness) and components of SC (network ties and trustworthiness) through existing prior research and investigated the factors that affected entrepreneurial intention. The first hypothesis of this study was that entrepreneurial temperament will have a significant impact on network ties of social capital, and the second hypothesis assumed that entrepreneurial temperament will have a significant effect on the trustworthiness of social capital. Finally, the second hypothesis assumed that social capital will have a significant impact on entrepreneurial intentions. We collected 175 data using questionnaires for people who have not yet started a start-up. And we used the Structure Equation Modeling (SEM) to evaluate the collected data and to test the research model by the two step research procedure. Results - As a result, the innovativeness and proactiveness of ET have a significant effect on network ties and trustworthiness of SC, but the effect of risk-taking on risk-taking of SC is not significant. On the other hand, network ties and network ties of SC was revealed a significant effect on the EI. Conclusions - The implications of this article could be observed as mentioned in this paper. First, we found that entrepreneurial innovativeness and proactiveness are helpful in constructing SCs, but not risk-taking. These results demonstrated that ET of entrepreneurs is important factor in the formation of social capital. Second, the SC that an entrepreneur built before the start-up has a meaning for EI. In conclusion, ET was affected partially to EI mediated SC. It is academic in that ET and SC are independent from each other and have a mediating role between ET and EI, unlike those directly affecting EI. Although some important implications were found in this study, this study had some limitations and we hope that future research will be complemented.

The Effects of Mixer Geometry on Hydraulic Turbulence : Computational Modeling (3-D 전산유체를 이용한 급속혼화조 형상에 따른 난류 유동장 연구)

  • Park, No-Suk;Kim, Sung-Hoon;Park, Heekyung
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.7
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    • pp.1173-1182
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    • 2000
  • The rapid mixing process has been considered as an important step in water treatment. Since the coagulant dispersion into raw water by rapid mixer can influence on the flocculation and filtration efficiency, many researchers have developed various devices and mixing methodologies. Until now, they focused attention on only coagulant dose, pH. rotating velocity and G value but overlooked the real turbulent flow and mixer geometry in rapid mixer. Therefore this paper questions the significance of turbulent flows in rapid mixer and focuses on the analysis of turbulent fluid in various mixer geometry with CFD(Computational Fluid Dynamics). The results of the jar-tests using various geometries indicate that the turbidity removal rate in a circular jar without baffle is higher than that of a circular with baffle. And the turbidity removal rate in Hudson jar is also founded to be higher than in the circular jar with baffle. The CFD simulation of velocity fields in jar demonstrates that the differences of removal rates among the various geometries are largely due to the formation of the different turbulent fluids fields with different geometries.

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A Study on the Strength Evaluation Method of Plate Structures with Penetration-holes (관통구를 갖는 판구조물의 강도평가 방법에 관한 연구)

  • Kim, Ul-Nyeon;Jang, Jun-Tae
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.6
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    • pp.476-484
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    • 2017
  • The purpose of this paper is to verify the structural integrity of a region with numerous penetration-holes in offshore structures such as semi-submersible rig and FPSO. In order to effectively check the yielding and buckling strength of plate members with penetration-holes, a screening analysis program was developed with the FE analysis tool to generate fine meshed model using the theoretical and analysis methods. When a hole is appeared in the plate structure members, the flow of stress is altered such that concentrations of stress form near the hole. Stress concentrations are of concern during both preliminary and detail design and need to be addressed from the perspectives of strength. To configure the geometrical shape, very fine meshed FE analysis is needed as the most accurate method. However, this method is practically impossible to apply for the strength verifications for all perforated plates. In this paper, screening analysis method was introduced to reduce analysis tasks prior to detailed FE analysis. This method is applied to not only the peak stress calculation combined stress concentration factor with nominal stress but also nominal equivalent stress calculation considering cutout effects. The areas investigated by very fine meshed analysis were to be chosen through screening analysis without any reinforcements for penetration-holes. If screening analysis results did not satisfy the acceptance criteria, direct FE analysis method as the 2nd step approach were applied with one of the coarse meshed model considering hole or with the very fine meshed model considering the hole shape and size. In order to effectively perform the local fine meshed analysis, automatic model generating program was developed based on the MSC/PATRAN which is pre-post FE analysis program. Buckling strength was also evaluated by Common Structure Rule (CSR) adopted by IACS as the stress obtained from very fine meshed FE analysis. Due to development of the screening analysis program and automatic FE modeling program, it was able to reduce the design periods and structural analysis costs.

Study of Biomass Estimation in Forest by Aerial Photograph and LiDAR Data (항공사진과 Lidar 데이터를 이용한 산림지역의 바이오매스 추정에 관한 연구)

  • Chang, An-Jin;Kim, Hyung-Tae
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.3
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    • pp.166-173
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    • 2008
  • Recently, problem of earth environment being attended with international issue, people are concerned about the environmentally-friendly and renewable biomass energy. Especially, the forest biomass is more important because Korea have to control carbon footprint for Kyoto Protocol and Convention on Climate Change. In case of Korea, forest area covers the land about 2/3 of all country. It is needed that more economical and efficient method to estimate the biomass by remote sensing data which include wide coverage and is progressed by one-step. In this study, we estimate forest biomass with LiDAR data and aerial photograph. Three biomass equation is used and estimate mean biomass of single tree and entire biomass in plots. The results are compared with field data. $R^2$ of the mean biomass of single tree is greater than 0.8 and that of entire biomass in plots is greater than 0.65. In conclusion, the method using remote sensing data is verified more economical and efficient than previous field data method.

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An Object-Oriented Analysis and Design Methodology for Security of Web Applications (웹 응용 보안을 위한 객체지향 분석·설계 방법론)

  • Joo, Kyung-Soo;Woo, Jung-Woong
    • Journal of Internet Computing and Services
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    • v.14 no.4
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    • pp.35-42
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    • 2013
  • Nowadays many tasks are performed using the Web. Accordingly, many web-based application systems with various and complicated functions are being requested. In order to develop such web-based application systems efficiently, object-oriented analysis and design methodology is used, and Java EE(Java Platform, Enterprise Edition) technologies are used for its implementation. The security issues have become increasingly important. For such reasons, Java EE provides mechanism related to security but it does not provide interconnections with object-oriented analysis and design methodology for developing web application system. Consequently, since the security method by Java EE mechanism is implemented at the last step only, it is difficult to apply constant security during the whole process of system development from the requirement analysis to implementation. Therefore, this paper suggests an object-oriented analysis and design methodology emphasized in the security for secure web application systems from the requirement analysis to implementation. The object-oriented analysis and design methodology adopts UMLsec, the modeling language with an emphasis on security for the requirement analysis and system analysis & design with regard to security. And for its implementation, RBAC (Role Based Access Control) of servlet from Java EE technologies is used. Also, the object-oriented analysis and design methodology for the secure web application is applied to online banking system in order to prove its effectiveness.

Typeface Design 'Arita' for Typographic Identity (타이포그래픽 아이덴티티를 위한 글자꼴 '아리따')

  • Ahn, Sang-Soo;Lee, Yong-Je;Han, Jae-Joon
    • Archives of design research
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    • v.19 no.6 s.68
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    • pp.33-38
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    • 2006
  • The development of the typeface 'Arita' presents a method and its following results for a corporate typographic identity. Amore pacific established a strategy for a typographic identity as for their high quality corporate culture and as a first step for it was to develop their corporate typeface 'Arita'. The typeface 'Arita' which pursues sharing and accompanying was developed to be used in the body text to enhance the function of the typography. What was needed to develop this typeface for Amore pacific was first, understanding of the corporation, and second, vision to present new direction for a typeface and its appropriate supervision, and third, ability in designing. Therefore, under the leading of Hong-ik University's meta design research institute, the typeface 'Arita' was created by in collaboration with Seoul women's university's modeling research institute and the typeface design specialty company, type space and the design company, Ahn-graphics. There are two kinds of weight in 'Arita' typeface, one is normal 'AritaM' and the other is semibold 'AritaSB'. 'Arita' is produced into TrueTypeFont(TTF) for Windows Operating System and OpenTypeFont(OTF) for Macintosh Operating System.

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Projective Reconstruction Method for 3D modeling from Un-calibrated Image Sequence (비교정 영상 시퀀스로부터 3차원 모델링을 위한 프로젝티브 재구성 방법)

  • Hong Hyun-Ki;Jung Yoon-Yong;Hwang Yong-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.2 s.302
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    • pp.113-120
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    • 2005
  • 3D reconstruction of a scene structure from un-calibrated image sequences has been long one of the central problems in computer vision. For 3D reconstruction in Euclidean space, projective reconstruction, which is classified into the merging method and the factorization, is needed as a preceding step. By calculating all camera projection matrices and structures at the same time, the factorization method suffers less from dia and error accumulation than the merging. However, the factorization is hard to analyze precisely long sequences because it is based on the assumption that all correspondences must remain in all views from the first frame to the last. This paper presents a new projective reconstruction method for recovery of 3D structure over long sequences. We break a full sequence into sub-sequences based on a quantitative measure considering the number of matching points between frames, the homography error, and the distribution of matching points on the frame. All of the projective reconstructions of sub-sequences are registered into the same coordinate frame for a complete description of the scene. no experimental results showed that the proposed method can recover more precise 3D structure than the merging method.

The Comparison of Beam Data between Measured Beam Data and Calculated Beam Data Using Treatment Planning System (6 MV 광자선의 측정데이터와 치료계획장치에 의한 계산데이터의 비교)

  • Park Sung Kwang;Cho Byung Chul;Cho Heung Lae;Ahn Ki Jung
    • Progress in Medical Physics
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    • v.16 no.3
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    • pp.125-129
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    • 2005
  • The first step in the commissioning procedure of a treatment planning system is always verification of the basic beam data. In this work, we have measured POD curves and beam profiles between 1 $\times$ 1 cm$^{2}$ and 40 $\times$ 40 cm$^{2}$ . In an attempt, Pinnacle 7.4f detect discrepancies between predicted dose distribution and delivered dose distribution. The discrepancies between measurement data and caculation data was found. The delivered dose was underestimated in field but overestimated out of field. The D$_{max}$ depth of 1 $\times$ 1 cm$^{2}$ was reduced about 2 mm. For the larger field size ($\geq$4$\times$4 cm$^{2}$, the beam profile and PDD curve showed good agreement between measurement data and calculation data.

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