• Title/Summary/Keyword: Surface Reflect Ratio

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The Reflected Property Analysis of 3D Laser Scanning System as Object Surface Materials (대상물 표면물질에 따른 3차원 레이저스캐닝 시스템의 반사특성분석)

  • Um, Dae-Yong;Kim, Ji-Hye
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.3
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    • pp.347-356
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    • 2009
  • Recently many kind of industry request 3D Modeling and visualize for object. So application of 3D laser scanning system is improved for 3D modeling and survey. But although application of scanner is steady improved, there are variety of caution error is contained in the result. There is request high quality survey for it is restricted by when field. To analysis what is consider major factor of reflect ratio about surface specification as ratio and characteristics accidental error. So this research use 3D laer scanning system what is adopted method of laser measurement for improvement accuracy 3D scan data. As a result we can check reflect volume will be improve as specification of survey object if it has high reflect ratio. It able to improve accuracy how laser scan data is revised by reflect volume.

Palynological Study of Akindonuma Moor in the Central Oh-u Backbone Range, Northeasternl Japan

  • Park, Ji-Hoon
    • The Korean Journal of Ecology
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    • v.25 no.1
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    • pp.45-49
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    • 2002
  • Pollen analyses and $^{14}$ C dating of the sediments of the Akindonuma moor, which is situated in a closed depression of an old landslide, were peformed in order to study the vegetation history of the montane zone of the Miyagi Prefecture, Northeast Japan. The main results are as follows: Two forest zones have been distinguished: 1) the A-I zone, or the Fagus-Quercus-Betula forest (R I stage, before about 11,700 yrs B.P.), and 2) the A-II zone, or the Fagus-Quercus forest (R II stage, after about 11,700 yrs B.P.). By comparing the geological section with the pollen diagram of the moor, it is assumed that the deposit environment of the Middle Part, which mostly consists of peat layers, is very stable. During the period, the Ulmus/Zelfkova pollen ratio was very low and small peak was not recognized. According to the preceding research, theme is a close relationship between the fluctuation of the Ulmus/Zelkova pollen ratio and the general trend of hillslope instability in the changing balance of temporature and precipitation Actually, Zelkova serrata tends to cover the footslope and the lower sideslope. Ulmus davidiana covers the footslope and the alluvial cone. Therefore, the fact that the Ulmus/Zeikova pollen ratio was very low and small peak was not recognized, is believed to reflect the stability of the earth's surface environment, which was estimated from the geological section.

Investigation of slope reinforcement with drilled shafts in colluvium soils

  • Lia, An-Jui;Wang, Wei-Chien;Lin, Horn-Da
    • Geomechanics and Engineering
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    • v.31 no.1
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    • pp.71-86
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    • 2022
  • In Taiwan, an efficient approach for enhancing the stability of colluvium slopes is the drilled shaft method. For slopes with drilled shafts, the soil arching effect is one of the primary factors influencing slope stability and intertwines to the failure mechanism of the pile-soil system. In this study, the contribution of soil arching effect to slope stability is evaluated using the FEM software (Plaxis 3D) with the built-in strength reduction technique. The result indicates the depth of the failure surface is influenced by the S/D ratio (the distance to the diameter of piles), which can reflect the contribution of the soil arching effect to soil stability. When α (rock inclination angles)=β (slope angles) is considered and the S/D ratio=4, the failure surface of the slope is not significantly influenced by the piles. Overall, the soil arching effect is more significant on α=β, especially for the steep slopes. Additionally, the soil arching effect has been included in the proposed stability charts. The proposed charts were validated through two case studies, including that of the well-known Woo-Wan-Chai field in Taiwan. The differences in safety factor (FoS) values between the referenced literature and this study was approximately 4.9%.

A Study on Establishment of Design Criteria for Development of New TWSIs (신형 점자블록 개발을 위한 설계원칙 설정 연구)

  • Shin, Dong-Hong;Seong, Ki-Chang;Kim, Sang-Woon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.22 no.1
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    • pp.29-37
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    • 2016
  • Purpose: Since the end of the 1990s the question of detecting blind and vision-impaired persons' tactile walking surface indicators have been rasied, the study of detecting tactile walking surface indicators has been started in Japan, German, and Sweden. Through the study, Japan, German, Sweden, and international's standard was revised. The Korean standard of tactile walking surface indicators was revised in 2013, the remarkable point was missed. Therefore, this study suggested deriving a range of types and dimensions of tactile walking surface indicators reasonable, and presenting the design principles for the development of new tactile walking surface indicators though domestic and international literature review. Method: This study was proceeded by comparison analysis of results from various tactile walking surface indicators' literature review from Japan, German, and Sweden, the most suitable range of types and dimensions was abstracted. Then, the range of types and dimensions was compared to the international standards and international reference standard, the ground rules were confirmed to apply new tactile walking surface indicators design. Results: Rationally, the wide and diameter of projecting line and projecting point should be downsized in order to improve detecting blind and vision-impaired persons' tactile walking surface indicators. And with same purpose, the ratio of the wide and diameter of projecting line and projecting point should be decided. The design of the tactile walking surface indicators in addition to the size and spacing of the protrusions should be to reflect the common elements that have been suggested a number of standard criteria. Implication: In this study, the design principles was derived through test results and theoretical studies, and new tactile walking surface indicators would need to be validated in local user.

An Image Quality Evaluation Model for Optical Strip Signal-to-Noise Ratio in the Target Area of High Temperature Forgings

  • Ma, Hongtao;Zhao, Yuyang;Feng, Yiran;Lee, Eung-Joo;Tao, Xueheng
    • Journal of Multimedia Information System
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    • v.8 no.2
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    • pp.93-100
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    • 2021
  • Under the time-varying temperature, the high-temperature radiation of forgings and the change of reflection characteristics of oxide skin on the surface of forgings lead to the difficulty of obtaining images to truly reflect the geometric characteristics of forgings. It is urgent to study the clear and reliable acquisition method of hot forging feature image under time-varying temperature to meet the requirements of visual measurement of hot geometric parameters of forgings. Based on this, this chapter first puts forward the quality evaluation method of forging feature image, which provides guarantee for the accurate evaluation of feature image quality. Furthermore, the factors that affect the image quality, such as the radiation characteristics of forgings and the photographic characteristics of cameras, are analyzed, and the imaging spectrum which can effectively suppress the radiation intensity of forgings is determined. Finally, aiming at the problem that the quality of image acquisition is difficult to guarantee due to the drastic change of radiation intensity of forgings under time-varying temperature, an image acquisition method based on minimum signal-to-noise ratio (SNR) based laser light intensity adaptation is proposed, which significantly improves the definition of feature light strips in forging images at high temperature, and finally realizes the clear acquisition of feature images of large-scale hot forging under time-varying temperature.

Distorted Bounding Surface of Clay with Consideration of the Effect of Temperature on Shearing Response (전단시 온도 영향을 고려한 점성토의 왜곡 경계면 모델 개발)

  • Woo, Sang Inn;Yune, Chan-Young
    • Journal of the Korean Geotechnical Society
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    • v.36 no.12
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    • pp.117-124
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    • 2020
  • The present research focuses on a methodology to describe shearing response of clay with respect to temperature. An increase of temperature shifts the normal consolidation line to move down in the plane of void ratio and mean effective stress. The critical state line, however, does not move as much as the normal consolidation line in accordance with temperature increase. As temperature increase, therefore, the difference between the critical state mean effective stress and the pre-consolidation pressure reduces. To reflect this easily, the present study applies a bounding surface consisting of two parts divided by the critical state mean effective stress. This study calibrated a bounding surface for the soft Bangkok clay and performed elemental simulation for undrained triaxial compression tests. The elemental simulation showed that the model can describe the mechanical response upon temperature of clay without complex hardening and evolution rules compared to the experimental data.

Analysis of Energy Concentration Characteristics of Heliostat used in 200kW Tower Type Solar Thermal Power Plant (200kW 탑형 태양열발전시스템에서 사용되는 Heliostat의 집열특성 분석)

  • Park, Young-Chil
    • Journal of the Korean Solar Energy Society
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    • v.31 no.3
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    • pp.80-88
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    • 2011
  • Heliostat in the tower type solar thermal power plant is a sun tracking mirror system to reflect the solar energy to the receiver and the optical performance of it affects to the efficiency of whole power plant most significantly. Thus a solid understanding of heliostat's energy concentration characteristics is the most important step in designing of the heliostat field and the whole power plant. The work presented here is the analysis of energy concentration characteristics of heliostat used in 200kW solar thermal power plant, where the receiver located at 43m high in tower has $2{\times}2$m rectangular shape. The heliostat reflective surface is formed by 4 of $1{\times}1$m flat plate mirror facet and the mirror facet is mounted on the spherical frame. The direct normal incident radiation models in vernal equinox, summer solstice, autumnal equinox and winter solstice are first derived from the actually measured data. Then the intercept ratio, heat flux distribution and total energy collected at the receiver for the heliostats located in the various places of the heliostat field are investigated. Finally the effect of mirror facet installation error on the optical performance of the heliostat is analyzed.

Physical Marine Environment at the north of Wando and Gogeumdo Receiving the Effluents from Land (육수의 영향을 받는 완도 및 고금도 북부 해역의 해황 특성)

  • Lee Moon-Ock;Park Il-Heum
    • Journal of Environmental Science International
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    • v.15 no.1
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    • pp.45-58
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    • 2006
  • In order to grasp physical characteristics of Ganajin Bay receiving the effluents from land, a comprehensive field surve)'has been conducted at the north of Wando and Gogeumdo in 2002. Water temperature was most high in September while most low in December. A high temperature in September was inferred to have caused by the dispersion of warm fresh water with favor of a dominant wind in autumn. However, salinity and sigma-t in situ was most low in September while most high in December. A low salinity (or density) in September turned out to reflect the influence of a dense rainfall in summer. Water temperature, salinity and density at the surface layer were lower than those at the bottom layer, except for December. Their horizontal profiles suggested the influence of effluents such as Tamjin River. Particularly, time series of water temperature acquired near the sluice and at the north channel of Wando tended to rise at the flood flow but fall at the ebb flow in accordance with the tide. The form ratio of the tide in the study area was $0.31\~0.32$ and the amplitude of the tide appeared to increase towards the west. Northeastward or southwestward flows prevailed in this area but the residual flows were all northeastward with a magnitude of $3\~4cm/s$.

Establishing Quantitative Evaluation Standards for the Shape Fitness test of Slacks (슬랙스 형태 적합성 평가의 정량적 평가 기준 설정)

  • Kim, Seonyoung
    • Fashion & Textile Research Journal
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    • v.18 no.5
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    • pp.695-707
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    • 2016
  • This study presents quantitative evaluation standards for the shape fitness test, conducted in the process of the slacks fit test. This study aims to quantify appearance sensory test of slacks for the objectification of qualitative evaluation methods in existing shape fitness tests. The subjects were women of standard body type between the ages of 18 and 24. Slacks differing in their ease in waist girth, hip girth, crotch length and knee length were designed to test their shape fitness. The gap volume distribution between the body and slack, angle of the baseline by body part, and ratio of total thickness from the sideline using 3D human body scan data (which reflect the results of the appearance sensory test) were presented as quantitative evaluation standards. There were less wrinkles in the wrinkle/overstretch and ease categories of the appearance sensory test; in addition, ease was adequate and small enough to comfortably perform basic human activities in the standing upright posture. The gap volume distribution analysis between body and slacks showed that curves increased in the slacks surface along with an increase of ease in slacks and suggested that wrinkles also increased. In the baseline's horizontal categories in terms of a $0^{\circ}$ horizontal angle, the range of angles were evaluated as adequate by the clothing expert group. The total thickness ratio of 0.5:0.5 divides into the sideline from the baseline.

Multi-physics Modelling of Moisture Related Shrinkage in Concrete (콘크리트 수분관련 수축에 관한 다중물리모델)

  • Lee, Chang-Soo;Park, Jong-Hyok
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.2
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    • pp.1-9
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    • 2009
  • Water binder ratio combine high-performance concrete shrinkage of less than 0.4 to determine the transformation to a total shrinkage of water to move outside and internal consumption of moisture due to drying shrinkage and autogenous shrinkage, and then, the relative humidity changes and strain to be approached by surface physics describe the relationship between self-desiccation and autogenous shrinkage was set. To verify the self-desiccation in the humidity shrinkage and humidity measurements performed, and the research model, Tazawa, CEB-FIP model than to let the measure and the most similar results in this study based on self-desiccation model, autogenous shrinkage didn't represent the linear shrinkage by the drying shrinkage of the external moving but exponential relationships, unlike with the nature and rapid in the early age properly describes the attributes in shrinkage could see. After this research to move moisture and to reflect the shrinkage model, temperature, moisture transfer, strain analysis by multi-physics model is very similar to the results of mock-up specimen measurements performed for this research, the value measured by the internal consumption of moisture, therefore self-desiccation and a multi-physics model considering autogenous shrinkage might be relevant.