• Title/Summary/Keyword: Flat Works

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Evaluation of Bending Characteristics for Carbon FRP Structure having Circle Cross-section (원통 CFRP 구조재의 굽힘 특성 평가)

  • Kim, Jung-Ho;Kim, Ji-Hoon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.20 no.2
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    • pp.202-206
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    • 2011
  • Works on the strength and stiffness in the structural members are carried out widely with various material and cross-sections with ever increasing safety concerns, they are presently applied in various fields including railroad trains, air crafts and automobiles. In addition to this, problem of lighting structural members became important subject by control of exhaust gas emission, fuel economy and energy efficiency. So, Light weight of member structures is necessary for the high performance and various functions. In this study, the CFRP flat and circular member was manufactured by CFRP prepreg sheet in autoclave. Carbon FRP is an anisotropy material whose mechanical properties change with its fiber orientation angle, so this study apply to the effects of the fiber orientation angle on the bending characteristics of the member. Each CFRP flat and circle are compared by strength and stiffness.

A Study on a Quantitative Measurement of Contact Pressure Between two Rough Flat SurFaces by Means of Ultrasonic Waves. (초음파를 이용한 이체 평면접촉부의 정량적인 접촉압력 측정에 관한 연구)

  • 김경모;정인성
    • Journal of the Korean Society of Safety
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    • v.5 no.3
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    • pp.8-26
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    • 1990
  • It is important to have exact information about the contact pressure distribution in the design of connected parts of machines and structures. In previous works, stress analyses on a two body contact problem have been carried out in large numbers. Besides, the measurement of contact stress is important to confirm the adequateness of the theoretical analysis, to verify appropriateness of Hertzian contact theory and to know the practical pressure distribution, but an excellent measuring method con't be found at present. Therefore, a quantitative measurement of contact pressure by means of ultrasonic waves using a normal probe and an angle has been proposed to measure the contact pressure distribution between two rough flat surfaces. At first, in a new proposed calibration method, the relation between mean contact pressure and sound pressure of reflected waves is obtained by using calibration blocks with various surface roughnesses made of the same material as the rectangular section beams And then, this experimental results are compared with the analytical ones, and the utility of this method is discussed.

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Apparel Design and Pattern Construction Utilizing Expressive Properties of Corset Look (코르셋 룩의 표현적 특성을 활용한 의상디자인 및 패턴제작)

  • Yoon, Jin-Ah
    • Journal of the Korea Fashion and Costume Design Association
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    • v.8 no.2
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    • pp.159-170
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    • 2006
  • This study aims to examine the expressive properties of contemporary corset, and to develop designs and produce patterns for corset look clothes. Through these courses, it develops a pattern that may all meet the exactness, functionality and aesthetic aspects of a pattern and provides materials that may help create a corset look design in the course of actuallymaking a garment. Based on the elements mentioned above, a total of three (3) real works were developed and their patterns were created. The patterns include two (2) flat patterns and one (1) patterns using the draping method. The results found in the course of creating works and patterns are as follows: With new corset look designs, this study was able to artificially highlight the body and express the beauty of costume through revelation of the body In addition, it explored the possibility that the phenomenon that underwear becoming outerwear may be a new idea in dress designing.

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Time Dependent Morphological Changes around the Closure Gap in Saemankeum (새만금 방조제 물막이 구간 주변에서의 지형변화예측(수공))

  • 박영욱;어대수;박상현
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2000.10a
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    • pp.365-370
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    • 2000
  • Sea dike construction for the tidal flat reclamation works in estuary and coast may change the characteristics of tidal motion and wave conditions in the region. In turn, a new hydraulic condition provides the impacts on sediment transport pattern and forms a new morphological environment. Also, morphological changes during the closure works of sea dike are closely related with a safy of sea dike. Therefore, the prediction of morphological changes is required secure the safe closure work and the economic design of sea dikes. To investigate morphological changes due to sea dike construction, hydrodynamic changes of tides and waves have to be evaluated, then sediment transport and sea bottom changes are computed. Mathematical modelling is required for representation of interrelation of tidal motion, wave and sediment transport. In this study, numerical model MORSYS is applied to compute the hydrodynamics and morphological changes around the closure gap for Saemankuem dike. This model allows a flexible integration of the module for waves, currents, sediment transport and bottom changes.

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A Study on the Cognitive Process of Supervisory control in Human-Computer Interaction (인간-컴퓨터 작업에서 감시체계의 상황인지과정에 관한 연구)

  • 오영진;이근희
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.16 no.27
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    • pp.105-111
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    • 1993
  • Human works shift its roll from physical condition to the system supervisory control task In this paper safety-presentation configuration is discussed instead of well-known fault-warning configuration. Of paticular interest was the personal factor which include the cognitive process. Through a performance between each person information processing(d') and decision process($\beta$) was pointed out to explain the sensitivity of personal cognitive process. Impact of uncertainty effect the supervisor having doubt situations. These facts are released by the use of flat fuzzy number of $\beta$ and its learning rate R.

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A Case Study of Contemporary Textile Art in Loewe Craft Prize

  • Hyojeong Park;Jinyoung Kim
    • Journal of Fashion Business
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    • v.27 no.6
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    • pp.99-109
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    • 2023
  • Loewe Craft Prize is currently the most influential craft contest. During the contest, contemporary craftworks, as art with excellent aesthetic value, are selected as finalists but there are no enough studies on them as subjects. This study aimed to investigate contemporary textile pieces found in the fashion brand Loewe's Craft Prize, a Loewe Foundation Craft Prize and elucidate their expressive characteristics. The methodology of the study was a qualitative study that derives the expressive characteristics of the works within the scope of the study through case analysis along with theoretical reviews. The selection of research subjects was based on 22 works of textile pieces among the works selected as finalists for the last six years since the first year of the prize in 2016. The analysis of textile pieces showed first, the emphasis on traditional expression, second, the development of new expressive techniques for the material, and third, the pictorial character revealed in flat pieces. The expressive characteristics of contemporary textile art shown in the Loewe Foundation Craft Prize, derived based on such results were, first, the confirmation of the unique capabilities of craft through the inheritance of tradition, second, the rediscovery of textile properties through material experimentation, and third, the possibility of expanding the field of textile due to the pictorial character.

Development Needs and Direction of an Ecological Grading System of Korean Tidal Flats (한국 갯벌 생태 등급도의 개발 필요성과 방향)

  • Yoo, Jae-Won;Lee, Chang-Gun;Kho, Byung-Seol;Lee, Si-Wan;Han, Dong-Uk;Choi, Keun-Hyung;Kim, Chang-Soo;Hong, Jae-Sang
    • Ocean and Polar Research
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    • v.32 no.2
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    • pp.137-144
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    • 2010
  • There is a host of habitat assessment systems available to evaluate and grade tidal flat ecosystems in Korea. Nevertheless, we recognize the need to develop a better ecological scheme to improve reliability and accuracy given the importance of using an empirical approach in assigning grades to indicators and the limitation of current systems which evaluate tidal flats on a regional basis. A preferable system would be one that enables habitat mapping within a tidal flat, provides a diagnosis of ecological stress/health, has a high level of ecological relevance, communicability, and statistical robustness, and enables evaluation of diverse habitats within a tidal flat. The following points should be considered in framing such a system. Indicators should discriminate habitat quality into five to seven grades accomodating diverse characteristics and conservation value of a habitat, and the grading should be made from frequency distribution of indicators based on nationwide data.We suggest the following tasks in crafting such a system: i) The decision on selection of indicators should be made based on accuracy of assessment and practical application; ii) effects of physical habitat conditions on variability of indicators should be reflected; and, iii) further works on stress/health indicators should be addressed for adopting a multiple-indicator approach which reduces misdiagnosis.

A Linear Precoding Technique for OFDM Systems with Cyclic Delay Diversity (순환 지연 다이버시티를 사용하는 OFDM 시스템을 위한 선형 프리코팅 기법)

  • Hui, Bing;Kim, Young-Bum;Chang, Kyung-Hi
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.3A
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    • pp.197-204
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    • 2009
  • Cyclic delay diversity (CDD) is considered a simple approach to exploit the frequency diversity, to improve the system performance in orthogonal frequency division multiplexing (OFDM) systems. Also, the linear preceding technique can significantly improve the performance of communication systems by exploiting the channel state in formation (CSI). In order to achieve enhanced performance, we propose applying linear preceding to the conventional CDD-OFDM transmit diversity schemes over Rayleigh fading channels. The proposed scheme works effectively with the accurate CSI in time-division-duplex (TDD) OFDM systems with CDD, where the reciprocity is ass umed instead of channel state feedback. For a BER of $10^{-4}$ and the mobility of 3 km/h, simulation results show that a gain of 6 dB is achieved by the proposed scheme over both flat fading and Pedestrian A (Ped A) channels, compared to the conventional CDD-OFDM system. On the other hand, for a mobility of 120 km/h, a gain of 2.7 dB and 3.8 dB is achieved in flat fading and Vehicular A (Veh A) channels, respectively.

A Study on Power loading Experiment & Performance Analysis for Dynamic Transient Effect of a Turbo-shaft Engine with Free Power Turbine (분리 축 가스 터빈 엔진의 동역학적 천이 효과를 고려한 성능 해석 및 부하 인가 시험에 관한 연구)

  • Kim Gyoung-du;Yang Soo-seok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.8 no.3
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    • pp.17-26
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    • 2004
  • In this paper, power transmission systems converts the shaft power of a Turbo-shaft Engine with Free Power Turbine into the generator power and be composed of a method being supplied in the thrust motor driving a propellers. Being used this, Gas turbine engine works to flat rating about 110 kw (147 shp) that the thrust motor be extremely supplied from the engine of 317shp. In this test equipment, the engine is installed with the flywheel being able to the damping function when happen to the varying load between gas turbine engine output-shaft and generator. Then if the flywheel of inertial moment be not considered, the generator and motor not get the required power from the engine for raising the load. Also it is certified that the engine works the abnormal operation. Hence the flywheel of inertial moment is determined the required range to do the performance analysis with the dynamic transient from the given and tested engine data. This system is able to get the required power after a mounting test with the redesigned flywheel.

Numerical Study on the Effect of the Wall Curvature on the Behaviors of the Impinging Sprays (충돌분무의 거동에 미치는 벽면곡률의 영향에 대한 수치해석 연구)

  • 고권현;유홍선
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.3
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    • pp.59-65
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    • 2004
  • In this paper a numerical study was performed for the effect of the wall curvature on the behaviors of fuel sprays impinging on the concave Surface. Actually, in the real diesel engines, a piston head has a curved shape for the purpose of the controlling the movement of fuel droplets and the mixture formation. For past decades, although many experimental and numerical works had been performed on the spray/wall impingement phenomena, the curvature effect of impinged wall was rarely investigated. The wall curvature affects on the behaviors of the secondary droplets generated by impingement and the concave wall obstructs the droplets to advance from the impinging site to outward. In present study, the simulation code was validated for the flat surface case and three cases of the different curvature were calculated and compared with the flat surface case for several parameters, such as the spray radius, the spray height and the position of vortex center of gas phase. The simulation results showed that the radial advance of the wall spray and the vortex is decreased with increasing the curvature. It was concluded that the curvature of the impinged wall significantly affects the behaviors of both the gas-phase and the droplet-phase.