• Title/Summary/Keyword: engine cover

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An Implementation of Search System based on Natural Language Index Incorporating considering Image Characteristics (이미지 특성을 고려한 자연어 색인 기반의 검색시스템 구현)

  • Kim, Jung-Yee;Lee, Ki-Wook;Lee, Kang-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.5 s.43
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    • pp.337-343
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    • 2006
  • The number of digital camera users is increasing rapidly and countless number of photos floats about on the internet especially through wide-spreading Cyworld and blogs. Though portraits cover a large percentage of those photos, because of the property rights, near entirety or such photos are unavailable for use by web-page producers, advertising companies, web-designers, and so on, who need a variety of portraits with differing expressions and characteristics. This study offers a search engine that incorporates image characteristics based on natural language index, which can provide a fast and reliable search result. It will create an opportunity for the digital photographers to mure easily sell their pictures and simultaneously provide the would-be users of the photos a better and easier way to find the pictures they are looking for. Once the search engine is realized, it will become possible to use not only the nouns as keywords and categories but also verbs in search of portraits revealing feelings, expressions, dressings, and other characteristics.

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Operating status of Korean coastal composite fishing boats by the questionnaire survey (설문조사를 통한 우리나라 연안복합어선의 조업 실태)

  • HWANG, Bo-Kyu;CHANG, Ho-Young;KIM, Min-Son
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.54 no.4
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    • pp.324-332
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    • 2018
  • We conducted a questionnaire survey to analyze the current status of the coastal composite fisheries, as well as the improvement point in designing a new type coastal composite fishing boat suitable for Korean fishing environments from April to August 2017. The questionnaire composed of 20 questions about the features of the coastal composite fishing boat and fishing work. The survey sites were selected to cover all parts of the country by considering the geographical position. The significance testing for the response results was accessed by ${\chi}^2$ test and ANOVA. The results revealed that more than half (59.1%) of the fishermen operated one day per voyage and operating alone topped with 22.5% in the number of crews, followed by 2 persons (20.3%) and 5 persons (22.1%). The navigation devices had a high rate of installation and GPS plotter ranked first in the devices. In addition, fish finder ranked first in fishing equipment, followed by net hauler. The most inconvenient work that they felt during the fishing operation was fish handing at 49.8% and other general fishing works like setting and hauling line, deck cleaning accounted for about 25%. The hardest work was the accident by ropes wrapped around propeller and the engine trouble came in second. The most inconvenient facilities to the present design of fishing boat was wheelhouse (76.7%), followed by fish hold (38.5%), and deck (35.1%). Furthermore, inconvenient points related to the movement of fishing gear, noise and vibration of engine, slippery deck and small fish hold exceeded 50%.

Urban Climate Impact Assessment Reflecting Urban Planning Scenarios - Connecting Green Network Across the North and South in Seoul - (서울 도시계획 정책을 적용한 기후영향평가 - 남북녹지축 조성사업을 대상으로 -)

  • Kwon, Hyuk-Gi;Yang, Ho-Jin;Yi, Chaeyeon;Kim, Yeon-Hee;Choi, Young-Jean
    • Journal of Environmental Impact Assessment
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    • v.24 no.2
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    • pp.134-153
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    • 2015
  • When making urban planning, it is important to understand climate effect caused by urban structural changes. Seoul city applies UPIS(Urban Plan Information System) which provides information on urban planning scenario. Technology for analyzing climate effect resulted from urban planning needs to developed by linking urban planning scenario provided by UPIS and climate analysis model, CAS(Climate Analysis Seoul). CAS develops for analyzing urban climate conditions to provide realistic information considering local air temperature and wind flows. Quantitative analyses conducted by CAS for the production, transportation, and stagnation of cold air, wind flow and thermal conditions by incorporating GIS analysis on land cover and elevation and meteorological analysis from MetPhoMod(Meteorology and atmospheric Photochemistry Meso-scale model). In order to reflect land cover and elevation of the latest information, CAS used to highly accurate raster data (1m) sourced from LiDAR survey and KOMPSAT-2(KOrea Multi-Purpose SATellite) satellite image(4m). For more realistic representation of land surface characteristic, DSM(Digital Surface Model) and DTM(Digital Terrain Model) data used as an input data for CFD(Computational Fluid Dynamics) model. Eight inflow directions considered to investigate the change of flow pattern, wind speed according to reconstruction and change of thermal environment by connecting green area formation. Also, MetPhoMod in CAS data used to consider realistic weather condition. The result show that wind corridors change due to reconstruction. As a whole surface temperature around target area decreases due to connecting green area formation. CFD model coupled with CAS is possible to evaluate the wind corridor and heat environment before/after reconstruction and connecting green area formation. In This study, analysis of climate impact before and after created the green area, which is part of 'Connecting green network across the north and south in Seoul' plan, one of the '2020 Seoul master plan'.

Economic Evaluation of ESS and Natural Gas Generator for Expansion of New and Renewable Generation (신재생발전 확대적용을 위한 ESS와 천연가스발전기의 경제성 평가)

  • JOO, YONGJIN;SHIN, JUGON;SEO, DONGKYUN;PARK, SEIK
    • Journal of Hydrogen and New Energy
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    • v.29 no.4
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    • pp.363-369
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    • 2018
  • This paper considers the alternative way to mitigate cost for REC instead of Photovoltaic (PV) panels with Energy Storage System (ESS). This study starts from an economic analysis of a 1 megawatt PV system without ESS. Several assumptions have been applied in consideration of the current domestic situation. Based on this result, the economic efficiency of PV with ESS improved. However, the reliance on government subsidies was very high. The alternative way to cover the fluctuation power from renewable energy was reviewed with economical and technical way. In case the natural gas engine applied to PV, the IRR and Levelized Cost of Electricity (LCOE) can be improved without ESS. And if small amount of additional REC, the IRR can be improved up to investment level.

Control System of Throttle Actrator for TCS (TCS용 스로틀 액츄에이터 제어 시스템)

  • 송재복;김효준;민덕인
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.3
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    • pp.191-201
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    • 1997
  • Accurate positioning of a throttle valve is required to implement the traction control system(TCS) which improves acceleration performance in slippery roads. In this research, position control system is developed for the main throttle actuator(MTA) system which uses one throttle actuation for small volume and DC servo motor for fast response. In order to drive DC motor, PWM signal generator and PWM amplifier were built and interfaced to the motor and controller. Digital PID control law is used as basic control algorithm. In order to prevent overshoot and improve accuracy, velocity profiles are generated and implemented whenever the targer throttle angle is given from the TCS controller. Thanks to velocity profiles, the control performance was very good and only one set of PID gains was used to cover the entire operating range. Also, the resolution of position is about 0.4$^{\circ}C$, which is better than that of stepping motor also used as throttle actuator in some products. The response time of the developed system is also fast enough to implement the engine control based TCS algorithm.

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A study on the burn-in test to accomplish high quality cockpit air of an ultra-sonic aircraft in the early stage of production (생산 초기 초음속 항공기 조종석의 고품질 공기 확보를 위한 burn-in test 연구)

  • Shin, Jae Hyuk;Park, Sung Jae;Seo, Dong Yeon;Jeong, Suheon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.10
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    • pp.871-876
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    • 2016
  • Abnormal odor similar with burning smell often appears at the cockpit in the beginning of ultra-sonic aircraft without air filter due to the heating of production materials remained at the bleed air duct. Sources of the odor should be removed by burn-in test before test flight in order to prevent pilot confuses order with emergency such as fire of engine. However, the present method cannot prevent abnormal odor completely at the high altitude flight because maximum temperature of flight is higher than it of burn-in-test. This paper suggests burn-in test improved based on the analysis of thermal conditions of high altitude flight. It is verified that the existing burn-in test cannot cover thermal conditions of high altitude flight due to the discontinuous flow control, high change rate of temperature per unit time and difference between limit temperature of condenser and turbine. In order to overcome the limitations of current methods, the new burn-in test with continuous flow control are suggested. The continuous flow control are achieved by ram air inlet control. The effect of suggested method are verified by ground tests and flight tests. The results show the bleed air temperature can cover the temperature of high altitude flight and prevent abnormal odor at the flight test.

Design Technique for Durability Improvement of Military Vehicle Clutch System (군용차량 클러치 내구수명 향상에 대한 연구)

  • Shin, Cheol-Ho;Kang, Tae-Woo;Kim, Sung-Gon;Kim, Seon-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.10
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    • pp.117-124
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    • 2019
  • Military Vehicles of the Korean army had been developed before 2004 and used manual transmissions. Manual transmissions contain a clutch system regulating the force from engine to transmission. In this study, a 2.5-ton military vehicle's clutch system was investigated. The existing clutch system had the characteristics that need to adjust the clearance between the clutch cover and release bearing. Improper clearance led to early wear of the clutch disk and failure of the clutch cover. To solve these problems, an improved clutch system was suggested and tested. The improved clutch system contains auto adjustment of the clearance and an enhanced clutch disk. To verify the improved clutch systems, 2 stage tests were conducted: an accelerated life test of the clutch system, and a driving test by trainee of driving more than 3,000km. As a result, the problems caused by the improper clearance adjustment were solved and this design was verified.

Numerical and Experimental Analysis of Micro Gas Turbine Heat Transfer Effect (초소형 가스터빈엔진 열전달 현상의 수치적 및 실험적 연구)

  • Seo, Junhyuk;Kwon, Kilsung;Choi, Ju Chan;Baek, Jehyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.2
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    • pp.153-159
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    • 2015
  • In this study, a 2-W micro-gas turbine engine was designed using micro-electro-mechanical systems (MEMS) technology, and analytical and experimental investigations of its potential under actual combustion conditions were performed. An ultra-micro-gas turbine contains a turbo-charger, combustor, and generator. A compressor, turbine blade, and generator coil were manufactured using MEMS technology. The shaft was supported by a precision computer numerical control machined air bearing, and a permanent magnet was attached to the end of the shaft for generation. An analysis found that the cooling effect of the air bearing and compressor was sufficient to cover the combustor heat, which was verified in an actual experiment.

Estimation on the Emission Reduction of SULEV LPG Vehicles (SULEV LPG 자동차의 배출가스 저감효과 평가)

  • Park, Jun-Hong;Lee, Jong-Tae;Kim, Sun-Moon;Kim, Jeong-Soo;Kang, Dae-Il;Lim, Yun-Sung;Han, Bo-Young
    • Journal of Korean Society for Atmospheric Environment
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    • v.28 no.1
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    • pp.68-76
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    • 2012
  • SULEV (Super Ultra Low Emission Vehicle) which is one of the emission standards in Fleet Average System introduced to Korea from 2009 is known as the most severe standard to achieve with internal combustion engine. Considering low sales volume of hybrid vehicles in Korea, vehicle manufacturers are required to develop SULEV technologies for conventional gasoline and LPG vehicles to meet the future Fleet Average standard. In this study, the comparison of emissions has been made between SULEV developed and ULEV LPG vehicles mainly produced in this time. To estimate the emission reduction of SULEV vehicles, CVS-75 and NIER test modes have been used. CVS-75 has been used for emission certification of gasoline and LPG vehicles. NIER modes cover various average vehicle speed and reflect Korean real driving patterns better than CVS-75. The test results show that SULEV LPG vehicles have very high potential to reduce $NO_x$ in regulated emissions, $N_2O$ in green house gases and toluene in VOCs. However, SULEV LPG vehicles don't affect much on the reduction of CO and total green house gases.

Building Wind Corridor Network Using Roughness Length (거칠기길이를 이용한 바람통로 네트워크 구축)

  • An, Seung Man;Lee, Kyoo-Seock;Yi, Chaeyeon
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.3
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    • pp.101-113
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    • 2015
  • The purpose of this study is increasing ventilation network usability for urban green space planning by enhancing its practicality and detail. A ventilation network feature extraction technique using roughness length($z_0$) was proposed. Continuously surfaced DZoMs generated from $z_0$(cadastral unit) using three interpolations(IDW, Spline, and Kriging) were compared to choose the most suitable interpolation method. Ventilation network features were extracted using the most suitable interpolation technique and studied with land cover and land surface temperature by spatial overlay comparison. Results show Kriging is most suitable for DZoM and feature extraction in comparison with IDW and Spline. Kriging based features are well fit to the land surface temperature(Landsat-7 ETM+) on summer and winter nights. Noteworthy is that the produced ventilation network appears to mitigate urban heat loads at night. The practical use of proposed ventilation network features are highly expected for urban green space planning, though strict validation and enhancement should follow. (1) $z_0$ enhancement, (2) additional ventilation network interpretation and editing, (3) linking disconnected ventilation network features, and (4) associated dataset enhancement with data integrity should technically preceded to enhance the applicability of a ventilation network for green space planning. The study domain will be expanded to the Seoul metropolitan area to apply the proposed ventilation network to green space planning practice.