• Title/Summary/Keyword: Concentrated Arrangement

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Numerical Investigation on Structural Behavior of a Lid with Stiffeners for Suction-installed Cofferdams (석션 가물막이 보강 상판의 구조 거동에 대한 수치해석 연구)

  • Kim, Jeongsoo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.10
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    • pp.7-17
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    • 2019
  • With increasing demand for large offshore infrastructures, suction cofferdams have been large, and the lid stiffener arrangement for a suction cofferdam has become a key element in cofferdam design to constrain the flexural deformation effectively. This study analyzed the changes in the structural behavior of a lid for a suction cofferdam due to lid stiffeners to provide insights into effective stiffener arrangements. By investigating conventional suction anchors, several stiffener patterns of a lid for a polygonal suction cofferdam were determined and analyzed. The structural performance of the stiffened lids was estimated by comparing the stress and deformation, and the reaction distributions on the edge of lid were investigated to analyze the effects of the stiffener arrangement on the lid-wall interface. Finite element analysis showed that radial stiffeners contribute dominantly to decreasing the stress and vertical deflection of the lids, but the stiffeners cause an increase in shear forces between the lid and wall; the forces are concentrated on the lid near the areas reinforced with radial stiffeners, which is negative to lid-wall connection design. On the other hand, inner and outer circumferential stiffeners show little reinforcement effects in themselves, while they can help reduce the stress and deformation when arranged with partial radial stiffeners simultaneously.

End Edge Cogging Force Minimization according to the Distance between Armatures of Stationary Discontinuous Armature PMLSM with Concentrated Winding (전기자 분산배치 집중권 PMLSM의 전기자 간격에 따른 단부 코깅력 최소화)

  • Kim, Yong-Jae
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.8
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    • pp.1241-1246
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    • 2013
  • Currently, The general transportation system arranges the armature on the full length of transportation lines. However, when this method is applied to the long distance transportation system, it causes an increase of material cost and manufacturing time. Thus, in order to resolve this problem, discontinuous arrangement method of the armature has been proposed. However, in the method of using stationary discontinuous armatures, mover can stop in the freewheeling section which is non-installations section when disturbance is generated and the mover can not be moved because armature control is impossible. Thus, the distance determination of armature is very important. Also, when the armature is arranged discontinuously the edge always exists due to the structure. Due to this edge, the cogging force is greatly generated during the entry and ejection of the mover to the armature. This cogging force causes thrust force ripple generating noise, vibration and decline of performance, it must be reduced. Therefore, in this paper, we examined the end edge cogging force generated by the stationary discontinuous armatures through 2-D numerical analysis using finite element method (FEM) and we figured out distance of armature for end edge cogging force minimization.

Numerical Simulation for the Subsurface Temperature Distribution Disturbed by Heat-Pump Operation (지열펌프 구동에 의한 지중 온도 분포 변화 모델링 연구)

  • Shin, Ji-Youn;Bae, Gwang-Ok;Lee, Kang-Kun
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.40-43
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    • 2006
  • Public demand for the heat pump system as a next generation energy equipment is increasing for its eco-friendly and cost-effective advantage. Many researches have been concentrated on how to calculate and develop its own efficiency, while the possible effect of the heat pump operation on the whole subsurface temperature distribution is relatively less considered, During the current study, subsurface temperature disturbance caused by seasonal surface temperature cycle in Busan area and general W-tube heat pump operation is simulated in 3-dimensional heterogeneous medium. It shows that subsurface deeper than 10m from the surface remains nearly unchanged throughout the 4 seasons and groundwater convect ion in highly permeable layer near the surface acts like a main path of heat plume from heat pump system, This implies the significance of detail descript ion in shallow sedimentary layer or highly permeable layer which plays an important role on the regional flow advection and heat transfer. Also, the effect of groundwater convection increases when the arrangement of the 2 injection pipes and 2 extract ion well is maintained parallel to groundwater flow. Therefore, more careful and detail investigation is required before installation and operation of heat pump system that it may not cause any possible change of microbial ecosystem in the shallow subsurface environment or 'contamination of temperature' for groundwater use as well as the loss of efficiency of the equipment itself. This can also help to design the optimized grouting system for heat pump.

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Drainage Control and Prediction of Slope Stability by GIS-based Hydrological Modeling at the Large Scale Open Pit Mine (GIS에 의한 대규모 노천광에서의 배수처리 및 사면안정 예측)

  • SunWoo, Choon;Choi, Yo-Soon;Park, Hyeong-Dong;Jung, Yong-Bok
    • Tunnel and Underground Space
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    • v.17 no.5
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    • pp.360-371
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    • 2007
  • This paper presents an application of drainage control and slope stability by GIS-based hydrological modeling to control the surface water from an operational point of view. This study was carried out on a region of Pasir open-pit coal mine, Indonesia. A detailed topographical survey was performed at the study area to generate a reliable DEM (Digital Elevation Model). Hydrology tools implemented in ArcGIS 9.1 were used to extract the characteristics of drainage system such as flow direction, flow accumulation and catchment area from DEM. The results of hydrological modeling and spatial analysis showed that current arrangement of pumping facility is not suitable and some vulnerable places to erosion exist on the bench face due to concentrated surface runoff. Finally, some practical measures were suggested to optimize the design of drainage system and to monitor the slope stability by the surface water management at the study region during heavy rainfall.

Effects of Fiber Arrangements on Stress Distributions over the Transverse Cross Section of Unidirectionally Continuous Fiber-reinforced Composites (단방향 연속 섬유 복합재 횡단면에서 섬유 배열에 따른 응력 분포 변화)

  • Choi, Soohoon;Ji, Wooseok
    • Composites Research
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    • v.33 no.1
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    • pp.30-37
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    • 2020
  • Stress distributions dependent on fiber arrangements are studied using the two-dimensional representative volume element (RVE) model for uni-directionally continuous fiber-reinforced composites subjected to transverse tensile loading. It is easily expected that the stresses around the fibers are concentrated mainly due to the stiffness mismatch between the fiber and matrix materials. In this presentation, it is shown that the stresses are not always increased although the distance between two fibers is shortened. The 2D RVE models, originally having a regular hexagonal fiber array, is utilized to study the effect of the fiber locations on the stress distributions. As the central fiber is relocated, the stress distributions around the fiber are obtained through finite element analysis. It is found that the stresses around the fiber are strongly dependent on the fiber distance as well as the angle between the loading direction and the line connecting two fibers.

The Basic Study On the Development of Ergonomic Integrated Bridge Alarm Management System (인간공학적 선교통합알람장치의 개발을 위한 기초 연구)

  • Yang, Young-Hoon;Yang, Chan-Su;Gong, In-Young;Lee, Bong-Wang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.11 no.1 s.22
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    • pp.17-22
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    • 2005
  • According to the development if the ships navigational equipment, a bridge system has been improved but a marine accidents by human error haven't been reduced Recently our interest is concentrated on a suitable ergonomic arrangement and design of the ships bridge equipment to reduce an error due to human factors. The bridge alarm system should be designed to recognize the alarm informations as soon as possible and to deliver it clearly. Internationally, the matter is being discussed on the BAMS(Bridge Alarm Management System) in a view if a ergonomic bridge design, but a practical design method is not getting result.. In this paper I would like to review an application approach of human engineering ergonomics to a bridge alarm system and propose a conceptual design if the Ergonomic Integrated Bridge Alarm Management System(EIBAMS)

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The improvement of the shellfish dredge vessel in Jeonnam province (전남 지역의 패류 형망어선의 개량)

  • PARK, Sang-Jun;JANG, Choong-Sik;AN, Young-Su;JIN, Song-Han;CHO, Youn-Hyoung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.2
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    • pp.162-171
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    • 2019
  • This study is aimed to develop an improved shellfish dredge vessel considering the increase of the fishing safety and welfare of fishermen in Jeonnam province. We visited five fishing village societies in Korea, and conducted field surveys and survey questions to investigate the current status. In order to solve the problems presented by the investigation, a general arrangement of the improvement vessel was written and adopted after meeting between the fishermen and research team, and calculated the initial stability in five loading conditions by using the Napa program. As a result of field surveys and survey questions, the existing vessel have buoyant materials under the bow and the warp pass through the wheel-house. In addition, most fishing equipment and nets are concentrated on a narrow stern, making it difficult to work efficiently. According to the survey, fishermen also responded that operation of casting and hauling is very inconvenient. The fishing equipment of the improvement vessel was rearranged, the size of the wheel-house and the crew room was increased, and we secured a basic welfare space. As a result of the initial stability test, the stability criteria of the fishing vessel were satisfied in all loading condition.

Why Women Remain Outsiders: A Comparative Study of Labour Market in Korea and Japan (여성은 왜 외부자로 남아 있는가?: 한국과 일본의 여성노동시장 비교연구)

  • Lee, Sophia Seung-yoon;AN, Juyoung;Kim, Yuhwi
    • 한국사회정책
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    • v.23 no.2
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    • pp.201-237
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    • 2016
  • This paper focuses on Korean and Japanese female workers participating in the outside (secondary) labour market, especially with an attention given to two aspects. First, we explain how females are 'more outsiders' than males in the labour market. Secondly, we investigate M-shape in the female labour market participation by focusing on different proportion of non-standard worker. Then, in order to explain why women keep on being more concentrated in the outer side of the labour market, we examine the development of three policies in Korea and Japan since 1990s. Labour market deregulation policy, female employment policy and lastly, family policy are examined as institutional arrangement. Lastly, we discuss on how institutional combination is associated with females' concentration in the outside labour market in Korean and Japanese dual labour market.

Unstable Behavior and Critical Buckling Load of a Single-Layer Dome using the Timber Elements (목재를 이용한 단층 지오데식 돔의 불안정 거동과 임계좌굴하중)

  • Hong, Seok-Ho;Ha, Hyeonju;Shon, Sudeok;Lee, Seungjae
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.2
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    • pp.19-28
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    • 2023
  • Timber structures are susceptible to moisture, contamination, and pest infestation, which can compromise their integrity and pose a significant fire hazard. Despite these drawbacks, timber's lightweight properties, eco-friendliness, and alignment with current architectural trends emphasizing sustainability make it an attractive option for construction. Moreover, timber structures offer economic benefits and provide a natural aesthetic that regulates building temperature and humidity. In recent years, timber domes have gained popularity due to their high recyclability, lightness, and improved fire resistance. Researchers are exploring hybrid timber and steel domes to enhance stability and rigidity. However, shallow dome structures still face challenges related to structural instability. This study investigates stability problems associated with timber domes, the behavior of timber and steel hybrid domes, and the impact of timber member positioning on dome stability and critical load levels. The paper analyzes unstable buckling in single-layer lattice domes using an incremental analysis method. The critical buckling load of the domes is examined based on the arrangement of timber members in the inclined and horizontal directions. The analysis shows that nodal snapping is observed in the case of a concentrated load, whereas snap-back is also observed in the case of a uniform load. Furthermore, the use of inclined timber and horizontal steel members in the lattice dome design provides adequate stability.

Development of Wedding Nail Art Based on the Design Elements of Wedding Dress -Focused on patterns and decorative details- (웨딩 드레스의 디자인 요소에 따른 웨딩 네일아트 개발 -문양과 장식적 디테일을 중심으로-)

  • Songhee Yang;Jiyoung Kim
    • Journal of Fashion Business
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    • v.28 no.4
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    • pp.149-166
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    • 2024
  • The purpose of this study is to analyze the design components of wedding dresses and develop wedding nail art based on this for total wedding styling that reflects the changing needs of consumers. As a research method, 750 dress photos posted on the wedding platform Wedding Friends were analyzed for patterns, decorative details, and images of the wedding dress, and nail art designs were developed based on the results. As a result of the analysis, there were many natural patterns of flowers and plants, no patterns, and geometric patterns, and the arrangement of patterns was the most common. Looking at the decorative details, there were many wrinkle details, slits, and cutouts such as flounce, frill, and ruffle, and there were many lace, sequins, and spangles in trimming. The application area of the decorative detail was concentrated on the entire dress or neckline. Based on the analysis results, five wedding nail art pieces suitable for total wedding styling were developed. Three works of the concept of "Elegant Bride" used the patterns and sparkling trimming of the wedding dress, and two works of the concept of "romantic moment" used voluminous embosses to express romantic sensibilities in 2D and 3D forms. Through this study, we were able to confirm the importance and value of nail art in total wedding styling and are expected to contribute to the development of creative nail art.