• Title/Summary/Keyword: 항공기술

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A Comparative Study on Power Tool Manufacturers' Products Spec. and Design Development Features - By the Case Study on BOSCH, BLACK&DECKER and KEYANG Electrics- (전동공구 회사의 제품사양별 디자인개발특성 비교연구 -보슈(BOSCH), 블랙앤데커(BLACK&DECKER), 계양전기 사례를 중심으로 -)

  • 채승진
    • Archives of design research
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    • v.17 no.1
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    • pp.383-392
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    • 2004
  • The power tools is the product using working power generated by electric motor. Many companies are manufacturing numerous devices. Main features of tools are included various assembled products, small, light and solid and durable enough to match several standards. Fundamental requirements for the product is excellent performance and convenience for use. The quality of them depends on the equipped motor'(s) capability, accuracy of gear and endurance against worn-out. By adapting the state-of-the-art parts, they could be used in the place from home to heavy industry broadly. They can be classified electronic drills, grinders, saws and sanders families for the household appliances. For industrial tools, bore drill, grinder, polisher, and driver drill are classified as special and high priced group. This study presents the strategy of power tool development of BOSCH, BLACK&DECKER and KEYANG. Their products were analyzed in terms of product line and product mix concept. Then they are examined by design elements, such as color, shape and material for housing. As an analysis method, the image scale parameter and criteria were applied to each company's product.

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Damage Analysis and Accuracy Assessment for River-side Facilities using UAV images (UAV 영상을 활용한 수변구조물 피해분석 및 정확도 평가)

  • Kim, Min Chul;Yoon, Hyuk Jin;Chang, Hwi Jeong;Yoo, Jong Su
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.1
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    • pp.81-87
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    • 2016
  • It is important to analyze the exact damage information for fast recovery when natural disasters cause damage on river-side facilities such as dams, bridges, embankments etc. In this study, we shows the method to effectively damage analysis plan using UAV(Unmanned aerial vehicle) images and accuracy assessment of it. The UAV images are captured on area near the river-side facilities and the core methodology for damage analysis are image matching and change detection algorithm. The result(point cloud) from image matching is to construct 3-dimensional data using by 2-dimensional images, it extracts damage areas by comparing the height values on same area with reference data. The results are tested absolute locational precision compared by post-processed aerial LiDAR data named reference data. The assessment analysis test shows our matching results 10-20 centimeter level precision if external orientation parameters are very accurate. This study shows suggested method is very useful for damage analysis in a large size structure like river-side facilities. But the complexity building can't apply this method, it need to the other method for damage analysis.

Status and perspective of gas turbine engine for automobiles (자동차용 가스터어빈 엔진의 현황 및 전망)

  • 김광호
    • Journal of the korean Society of Automotive Engineers
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    • v.9 no.3
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    • pp.10-14
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    • 1987
  • 우리나라는 이제 그동안의 꾸준한 노력의 결과로 자동차 수출국으로 발돋움하고 있으며 이 분야 에서으 선진국과의 경쟁이 점점 치열해질 전망이다. 이러한 세계 시장에서의 경쟁 대열에서 탈 락되지 않기 위해서는 무엇보다도 제품 품질의 향상, 원가의 절감 등이 이루어져야 할 것이며 이 에 대한 노력을 게을리 해서는 안될 것이다. 한편 이와는 별도로 좀더 다른 각도에서 자동차 공업의 방향을 고찰할 필요가 있다. 즉 미래에도 계속해서 현재의 왕복동 내연기관이 자동차 구동용으로 사용될 것인가 하는 점이다. 엔진의 성능 향상, 연비의 감소, 엄격한 배기가스 규 제에의 대처 등에 대한 연구가 활발히 진행되고 있지만 기술개발에는 한계가 있으며 제품은 점점 복잡하게 되어 결국은 제품가격 및 A/S 비용이 상승되는 역효과를 나타낼 가능성이 높다. 이에 세계적인 자동차 제조회사에서는 오래전부터 새로운 방식의 미래형 자동차 engine 개발에 착수 하였으며 계속적인 연구를 진행하고 있다. 이러한 미래형 자동차 engine의 대표적인 것으로 gas turbine engine이 있다. 가스터어빈이라 하면 우선 항공기용의 jet engine을 생각하게 된다. 그 외에 발전용으로 가스터어빈은 이용되고 있으며 근래 다시 등장한 자동차용의turbocharger 역시 가스터어빈의 한 응용분야라고 할 수 있다. turbocharger의 경우는 내연기관의 출력향상을 주 목적으로 내연기관에 부착되어 이용되고 있는 반면에 gas turbine engine은 기존의 내연기관을 대체하여 자동차 구동용으로 이용되는 점에 그 차이가 있다. 아직은 실용화되징 않았지만 미래형 자동차 기관으로서의 이용가능성이 높은 gas turbine engine을 다음에 간략히 소개하고자 한다. 생산량과 하천수에 의한 생산량과의 비는 풍건물의 경우 0.6, 매물의 경우 0.5였으며 감자의 경우는 0.2이하였다. 4. 염분용수 관개구와 하천수 관개구의 모든작물에서 풍건물 생산량과 축배량 사이에는 강한 직선적인 관계를 보였다. 보리, 감자의 작물 생산량과 축배량사이에도 선형의 관계가 성립되었으나, 밀과 옥수수의 매물 생산량과 축배량사이에는 곡선적인 관계를 나타내었다..18cm)에 필적되는 연평균 4.16cm로 나타났다. 5. 전체 시험구로부터으 연평균 토양유실량은 Sharpsburg 점질양토에 대한 S.C.S 한계허용치 10ton/ha/year 이내로 나타났다. 비처리구에서의 토양유실량은 평균 2.56ton/ha/year로 높게 나타난 반면 3개의 서로 다른 추리구인 비수구, 초생수로구 및 Bromegrass구에서는 각각 0.152, 0.192 및 0.290ton/ha/year로 낮은 결과를 가져왔다. 6. 평균 침전량에 대한 L.S.D. 검정 걸과 전시험구중 비처리구가 고도의 유의차를 나타낸 반면 비수구, 초생수로구 및 Bromegrass 목초구 간에는 아무런 유의차가 인정되지 않았다. 7. 농지보전 처리구인 배수구와 초생수로구는 비처리구에 비해 낮은 침두 유출량과 낮은 토양유실량을 나타내었다.구보다 14% 절감되는 것으로 나타났다.작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰

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Airborne Video as a Remote Sensor for Linear Target : Academic Research and Field Practices (선형지상물체에 대한 원격센서로서의 항공비디오 : 연구추세 및 실무에서 사용현황)

  • 엄정섭
    • Korean Journal of Remote Sensing
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    • v.15 no.2
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    • pp.159-174
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    • 1999
  • An important aspect of remote sensing research would be ultimately the production of research output so that operational people can directly use it. However, for the strip target, it is not certain how the research output in remote sensing helps the field user in adopting and utilizing the technology successfully. The relative limitation of traditional remote sensing systems for such a linear application is briefly discussed and the strength of videography are highlighted. Based on the postulated advantages of video as corridor sensor, a careful and extensive investigation has been made of research trends for airborne videography to identify how past research matches to demand of field clients. It is found that while video has been operationally used for strip target in field client communities, much research effort has been directed to area target, and relatively little towards the classification and monitoring of linear target. From this critical review, a very important step has been made concerning the practicality of airborne videography. The value of this paper is warranted in proposing a new concept of video strip monitoring(VSM) as future research direction in recognition of sensor characteristics and limitations. Ultimately, the suggestion in this paper will greatly contribute to opening new possibilities for implementing VSM, proposed as an initial aim of this paper.

Estimation of Individual Tree and Tree Height using Color Aerial Photograph and LiDAR Data (컬러항공사진과 LiDAR 데이터를 이용한 수목 개체 및 수고 추정)

  • Chang, An-Jin;Kim, Yong-Il;Lee, Byung-Kil;Yu, Ki-Yun
    • Korean Journal of Remote Sensing
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    • v.22 no.6
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    • pp.543-551
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    • 2006
  • Recently efforts to extract information about forests by using remote sensing techniques for efficient forest management have progressed actively. In terms of extraction of tree information using single remote sensing data, however, the accuracy of tree recognition and the quantity of extracted information is limited. The objective of this study is to carry out tree modeling in domestic environment applying the latest core technique for tree modeling using color aerial photographs and LiDAR data and to estimate the result of tree modeling. A small-scale coniferous forest was investigated in Daejeon. It was 0.77 that the $R^2$ of accuracy test of tree numbers that estimated with color aerial photography and LiDAR data. In terms of tree height, there was no difference between the estimated value and the field measurements in the case of the group accuracy test of the recently unchanged area. Moreover $R^2$ was 0.83 in the case of the individual accuracy test.

3D Thermo-Spatial Modeling Using Drone Thermal Infrared Images (드론 열적외선 영상을 이용한 3차원 열공간 모델링)

  • Shin, Young Ha;Sohn, Kyung Wahn;Lim, SooBong;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.4
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    • pp.223-233
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    • 2021
  • Systematic and continuous monitoring and management of the energy consumption of buildings are important for estimating building energy efficiency, and ultimately aim to cope with climate change and establish effective policies for environment, and energy supply and demand policies. Globally, buildings consume 36% of total energy and account for 39% of carbon dioxide emissions. The purpose of this study is to generate three-dimensional thermo-spatial building models with photogrammetric technique using drone TIR (Thermal Infrared) images to measure the temperature emitted from a building, that is essential for the building energy rating system. The aerial triangulation was performed with both optical and TIR images taken from the sensor mounted on the drone, and the accuracy of the models was analyzed. In addition, the thermo-spatial models of temperature distribution of the buildings in three-dimension were visualized. Although shape of the objects 3D building modeling is relatively inaccurate as the spatial and radiometric resolution of the TIR images are lower than that of optical images, TIR imagery could be used effectively to measure the thermal energy of the buildings based on spatial information. This paper could be meaningful to present extension of photogrammetry to various application. The energy consumption could be quantitatively estimated using the temperature emitted from the individual buildings that eventually would be uses as essential information for building energy efficiency rating system.

Accuracy Assessment of the Satellite-based IMERG's Monthly Rainfall Data in the Inland Region of Korea (한반도 육상지역에서의 위성기반 IMERG 월 강수 관측 자료의 정확도 평가)

  • Ryu, Sumin;Hong, Sungwook
    • Journal of the Korean earth science society
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    • v.39 no.6
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    • pp.533-544
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    • 2018
  • Rainfall is one of the most important meteorological variables in meteorology, agriculture, hydrology, natural disaster, construction, and architecture. Recently, satellite remote sensing is essential to the accurate detection, estimation, and prediction of rainfall. In this study, the accuracy of Integrated Multi-satellite Retrievals for GPM (IMERG) product, a composite rainfall information based on Global Precipitation Measurement (GPM) satellite was evaluated with ground observation data in the inland of Korea. The Automatic Weather Station (AWS)-based rainfall measurement data were used for validation. The IMERG and AWS rainfall data were collocated and compared during one year from January 1, 2016 to December 31, 2016. The coastal regions and islands were also evaluated irrespective of the well-known uncertainty of satellite-based rainfall data. Consequently, the IMERG data showed a high correlation (0.95) and low error statistics of Bias (15.08 mm/mon) and RMSE (30.32 mm/mon) in comparison to AWS observations. In coastal regions and islands, the IMERG data have a high correlation more than 0.7 as well as inland regions, and the reliability of IMERG data was verified as rainfall data.

Performance Comparison of Matching Cost Functions for High-Quality Sea-Ice Surface Model Generation (고품질 해빙표면모델 생성을 위한 정합비용함수의 성능 비교 분석)

  • Kim, Jae-In;Kim, Hyun-Cheol
    • Korean Journal of Remote Sensing
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    • v.34 no.6_2
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    • pp.1251-1260
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    • 2018
  • High-quality sea-ice surface models generated from aerial images can be used effectively as field data for developing satellite-based remote sensing methods but also as analysis data for understanding geometric variations of Arctic sea-ice. However, the lack of texture information on sea-ice surfaces can reduce the accuracy of image matching. In this paper, we analyze the performance of matching cost functions for homogeneous sea-ice surfaces as a part of high-quality sea-ice surface model generation. The matching cost functions include sum of squared differences (SSD), normalized cross-correlation (NCC), and zero-mean normalized cross-correlation (ZNCC) in image domain and phase correlation (PC), orientation correlation (OC), and gradient correlation (GC) in frequency domain. In order to analyze the matching performance for texture changes clearly and objectively, a new evaluation methodology based on the principle of object-space matching technique was introduced. Experimental results showed that it is possible to secure reliability and accuracy of image matching only when optimal search windows are variably applied to each matching point in textureless regions such as sea-ice surfaces. Among the matching cost functions, NCC and ZNCC showed the best performance for texture changes.

A tool development for forced striation and delineation of river network from digital elevation model based on ModelBuilder (모델빌더 기반 하천망의 DEM 각인 및 추출 툴 개발)

  • Choi, Seungsoo;Kim, Dongsu;You, Hojun
    • Journal of Korea Water Resources Association
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    • v.52 no.8
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    • pp.515-529
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    • 2019
  • Geospatial information for river network and watershed boundary have played a fundamental roles in terms of river management, planning and design, hydrological and hydraulic analysis. Irrespective of their importance, the lack of punctual update and improper maintenance in currently available river-related geospatial information systems has revealed inconsistency issues between individual systems and spatial inaccuracy with regard to reflecting dynamically transferring riverine geography. Given that digital elevation models (DEMs) of high spatial resolution enabling to reproduce precise river network are only available adjacent to national rivers, DEMs with poor spatial resolution lead to generate unreliable river network information and thereby reduce their extensible applicabilities. This study first of all evaluated published spatial information available in Korea with respect to their spatial accuracy and consistency, and also provides a methodology and tool to modify existing low resolution of DEMs by means of striation of conventional or digitized river network to replicate input river network in various degree of further delineation. The tool named FSND was designed to be operated in ArcGIS ModelBuilder which ensures to automatically simulate river network striation to DEMs and delineation with different flow accumulation threshold. The FNSD was successfully validated in Seom River basin to identify its replication of given river network manually digitized based on recent aerial photograph in conjunction with a DEM with 30 meter spatial resolution. With the derived accuracy of reproducibility, substantiation of a various order of river network and watershed boundary from the striated DEM posed tangible possibility for highly extending DEMs with low resolution to be capable of producing reliable riverine spatial information subsequently.

Suggestion of Customized Professional Guide Services through Domestic and Foreign Travel Platforms (국내외 여행 플랫폼을 통한 맞춤형 전문 가이드 서비스 제안)

  • Kim, Seung-In;Lee, Kaha
    • Journal of Digital Convergence
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    • v.17 no.9
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    • pp.421-428
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    • 2019
  • This study includes services that require six professional guides - health care, exhibition performance, restaurant, shopping, business and daily life - as well as a trip-based tour, along with solving existing problems that may occur on domestic and overseas trips, and proposes services that connect users with proven professional guides. As a result of previous research, the most needed services among overseas travel were air tickets, accommodation, transportation, and guides, but as Korea enters an aging society, professional guide services are expected to increase daily demand. Based on this, the service technology, user scenarios and brand development were presented. This Service Proposal provides users with a personalized guide to knowledge or experience that they have not previously known, providing them with a wealth of experience. In addition, guides can help develop new fields of expertise and help improve professional guides' capabilities. Finally, the platform service is meaningful in that it enables the creation of jobs by enabling everyone to engage in economic activities, as it allows users to provide services through their own capabilities while at the same time being convenient for them.