• 제목/요약/키워드: FLAT

검색결과 7,918건 처리시간 0.035초

여름철 엠보싱 샌드위치 패널의 열적 성능에 관한 연구 -평판 샌드위치 패널과 비교를 중심으로- (A Study on the Thermal Performance of Embossing Surface Sandwich Panel During the Summer)

  • 손철수
    • 설비공학논문집
    • /
    • 제12권10호
    • /
    • pp.917-924
    • /
    • 2000
  • The purpose of this research is to investigate the thermal performance of embossing surface sandwich panel and flat surface sandwich panel during the summer. To do this research, thermal performances in summer season at the six points of embossing surface sandwich panel and flat surface sandwich panel are investigated focusing on the temperature. Three kinds of embossing surface sandwich panel and one kind of flat surface sandwich panel are used for this research. At the same size of sandwich panel, the average temperature differences of flat surface sandwich panel between average temperature at the 0.5 mm below copper plate and average outside air temperature and surface temperature are higher than those of embossing surface sandwich panel. The average heat transfer rate of flat surface sandwich panel is higher than that of embossing surface sandwich panel. More study will be needed about the size of diameter and height of embossing, and materials of embossing surface sandwich panel.

  • PDF

공동주택 구조 유형별 바닥진동 및 바닥충격음 특성 (A Study on the Characteristics of the Floor Impact Noise and Vibration According to Structure Types of Apartment House)

  • 이규동
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2009년도 추계 학술논문 발표대회
    • /
    • pp.35-39
    • /
    • 2009
  • Recently, the flat-plate structure is widely used because it has many advantages such as reduction of story height, long span etc than the RC rahmen structure. Furthermore, application of the flat-plate is on the increase because of flexible plan unlike wall structure. Long span have been at a disadvantage for vibration serviceability evaluation, however studies about vertical direction vibration of flat-plate structure has not been carried out. This study analysis the characteristics according to slab structure to make an experiment on vibration and floor impact noise for the flat-plate structure in construction performance laboratory in Kolon E&C R&D center, the flat-plate structure applied to the post-tension method, and the wall structure in apartment houses.

  • PDF

평판형 집열기에서 일사성분의 유효성에 관한 연구 (Research on Effective Use of Radiation for Flat plate Type Collector)

  • 최성우;정성식;하종률;하도양개
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2004년도 춘계학술대회
    • /
    • pp.2135-2140
    • /
    • 2004
  • This study represented experimental research on the flat plate solar collector. For the flat plate Solar system, it is sensitive of the Global radiation. In Actually, it suppose to be dependent on the direct radiation. Also, the existing method's factors are depend upon Global radiation in the flat plate collector system. therefore it needs which is depend upon direct radiation. In this experiment, the flat plate collector is used for obtaining the method's factors of the direct radiation. As a result, the correct $({\tau}{\alpha})_e$ is found out for practical value.

  • PDF

Inversion-Based Robust Output Tracking of Differentially Flat Nonlinear Systems

  • Joo, Jin-Man;Park, in-Bae;Park, Yoon-Ho
    • Transactions on Control, Automation and Systems Engineering
    • /
    • 제3권1호
    • /
    • pp.21-26
    • /
    • 2001
  • In this study, we propose a two degree of freedom robust output tracking control method for a class of nonlinear system. We consider hyperbolically nonminimum phase single-input single-output uncertain nonlinear systems. We also consider the case that the nominal input-state equation is differentially flat. Nominal stable state trajectory is obtained in the flat output space via the flat output. Nominal feedforward control input is also computed from the nominal state trajectory. Due to the nature of the method, the generated flat output trajectory and control input are noncausal. Robust feedback control is designed to stabilize the systems around the nominal trajectory. A numerical example is given is given to demonstrate that robust tracking is achieved.

  • PDF

반도체용 저온 열처리로의 Flat Zone 확장 및 온도편차 감소에 관한 연구 (Study on the Flat Zone Expansion and Temperature Deviation Reduction of Low Temperature Furnace for Semiconductor Process)

  • 주강우;심승술;장혁;이유영;김광선
    • 반도체디스플레이기술학회지
    • /
    • 제13권4호
    • /
    • pp.83-90
    • /
    • 2014
  • This paper is about the yield rate of lower temperature furnace for wafer heat-treatment. The flat-zone that the temperature in furnace has uniform distribution specific area is the significant variable to the yield rate. In this study, we researched about the ways how to widen the flat zone in the furnace using CFD. As a result, we confirmed that the characteristic of the flat-zone was changed when SCU(Super Cooling Unit) was used. We considered temperature control with above.

평판형 광원에서 제논 플라즈마의 전기적 및 광학적 특성 (Electrical and Optical Properties of Xe Plasma in Flat Lamp)

  • 최용성;이경섭
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
    • /
    • pp.71-74
    • /
    • 2006
  • Discharge of the flat lamp lighting source research arc requested very much. For improving brightness, life time, efficiency of flat lamp, plasma diagnosis of the flat lamp lighting source to understand property of lighting source is very important. distance of discharge electrode is 5.5mm and width is 16.5mm, we measured electron temperature and electron density measured with single langmuir probe in flat lamp. we tested the discharge from 100 Torr to 300 Torr pressure. the Pulse is rectangular pulse with frequency 20kHz and Duty ratio 20%. Resultly, electron temperature decreases and electron density increase as increase the gas pressure and electron temperature decreases and electron density increase as increase the voltage.

  • PDF

시화 갯벌식생범위의 시-공간적 변이 분석 (The Analysis of Temporal and Spatial Variation on the Vegetation Area of the Siwha Tidat Flat)

  • 정종철
    • 환경영향평가
    • /
    • 제20권3호
    • /
    • pp.349-356
    • /
    • 2011
  • This research is aim to analyze of changing landscape and according to phenological cycle from image information of coastal environment obtained by multi-media were analyzed by camera and satellite image. The digital camera and satellite image were used for tidal flat vegetation monitoring during the construction of Sihwa lake. The vegetation type and phenological cycle of Sihwa tidal flat have been changed with the Sihwa lake ecosystem. The environment changes of Sihwa tidal flat area and ecological change were analyzed by field work digital camera images and satellite images. The airborne, UAV and satellite images were classified with the changed elements of coastal ecological environment and tidal flat vegetation monitoring carried out the changed area and shape of vegetation distribution with time series images.

수직진동 사용성을 고려한 플랫 플레이트 슬래브의 최소두께 제안 (Minimum Thickness of Flat Plate Slab Satisfying Floor Vibration Criteria)

  • 이민정;김동현;한상환
    • 한국소음진동공학회논문집
    • /
    • 제16권6호
    • /
    • pp.574-581
    • /
    • 2006
  • Flat plate slab systems are more economical rather than reinforced concrete frame systems because flat plate slab system reduces story height. Furthermore flat plate systems are more popularly needed in construction practice due to flexibility of plan. Korean Concrete Provisions 2003 provide the minimum thickness of the slab that satisfies serviceability requirement to the static displacement. However, floor thickness in residence buildings may not satisfy the floor vibration criteria although the thickness satisfies the serviceability requirements in current design provisions. This study estimates the dynamic properties of floor vibration for existing flat plate slabs, and proposes the slab thickness satisfying the floor vibration criteria. The dynamic response analysis using finite element method and reliability analysis are carried out for this Purpose.

Effects of Customized 3D-printed Insoles on the Kinematics of Flat-footed Walking and Running

  • Joo, Ji-Yong;Kim, Young-Kwan
    • 한국운동역학회지
    • /
    • 제28권4호
    • /
    • pp.237-244
    • /
    • 2018
  • Objective: Flat-footed people struggle with excessive ankle joint motion during walking and running. This study aimed to investigate the effects of customized three-dimensional 3D-printed insoles on the kinematics of flat-footed people during daily activities (walking and running). Method: Fifteen subjects (height, $169.20{\pm}2.61cm$; age, $22.87{\pm}8.48years$; navicular bone height, $13.2{\pm}1.00mm$) diagnosed with flat feet in a physical examination participated in this study. Results: The customized 3D-printed insoles did not significantly affect 3D ankle joint angles under walking and running conditions. However, they shifted the trajectory of the center of pressure (COP) laterally during fast walking, which enhanced the load distribution on the foot during the stance phase. Conclusion: The customized 3D-printed insoles somewhat positively affected the pressure distribution of flat-footed people by changing the COP trajectory. Further research including comparisons with customized commercial insoles is needed.

ON 𝜙-w-FLAT MODULES AND THEIR HOMOLOGICAL DIMENSIONS

  • Zhang, Xiaolei;Zhao, Wei
    • 대한수학회보
    • /
    • 제58권4호
    • /
    • pp.1039-1052
    • /
    • 2021
  • In this paper, we introduce and study the class of 𝜙-w-flat modules which are generalizations of both 𝜙-flat modules and w-flat modules. The 𝜙-w-weak global dimension 𝜙-w-w.gl.dim(R) of a commutative ring R is also introduced and studied. We show that, for a 𝜙-ring R, 𝜙-w-w.gl.dim(R) = 0 if and only if w-dim(R) = 0 if and only if R is a 𝜙-von Neumann ring. It is also proved that, for a strongly 𝜙-ring R, 𝜙-w-w.gl.dim(R) ≤ 1 if and only if each nonnil ideal of R is 𝜙-w-flat, if and only if R is a 𝜙-PvMR, if and only if R is a PvMR.