• Title/Summary/Keyword: cover channel

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Numerical Analysis of Cooling Channels for Injection Molding Cycle Time Improvement of Plastic Horn Cover for an Automobile (차량용 플라스틱 혼 커버의 사출성형 싸이클 타임 개선을 위한 냉각 채널의 수치해석 연구)

  • Han, Seong-Ryoel
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.5
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    • pp.84-90
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    • 2018
  • When producing a plastic horn cover for an automobile, since the interval between the ribs on the inner surface is narrow, conventional cooling channels cannot be applied and cooling of the mold is difficult. For this reason, the molding operation cannot be completed within a set cycle time. In this study, a conformal cooling channel was applied on the mold to solve the cooling problem. Injection molding simulation was carried out to confirm the effectiveness of the conformal cooling channel. In the analysis results, the mold temperature at the rib section decreased by 33%, and the mold temperature also decreased by 31%. This reduction in temperature allowed for molding within a set cycle time and demonstrated the effectiveness of the conformal cooling channel.

Comparison of Land Surface Temperatures Derived from Surface Emissivity with Urban Heat Island Effect (지표 방사율에 의한 지표온도와 도시열섬효과 비교)

  • Jeong, Jong-Chul
    • Journal of Environmental Impact Assessment
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    • v.18 no.4
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    • pp.219-227
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    • 2009
  • Because of urban development and changed land cover types, It is very important to acquire pixel unit of land surface temperature(LST) information when the heat island effect(HIE) of regional area are investigated. The brightness temperature observed by satellite is very useful for assessing the pixel unit of LST distributions for the analysis of thermal environment problems of urban areas. Also, satellite land cover data are very useful to our understanding of surface conditions of study areas. In this study, brightness temperature information of Landsat TM thermal channel was analyzed and compared with land cover information of Jeon-ju city. The atmospheric correction of TM thermal channel carried out to explain for compared LST long term monitoring errors. However, simple estimation and evaluation methods to find a physical relationship between LST from satellite images and in-situ data are compared with reference channel emissivity.

Exploratory Research on the Success Factors of YouTube Music Cover Channel Based on the Post Acceptance Model(PAM) and Flow Theory (후기기술수용모형(PAM)과 플로우(Flow)이론을 기반으로 한 유튜브 커버음악 채널의 성공 요인에 대한 탐색적 연구)

  • Lee, Jin-Hyung;Chae, Myung-Sin;Jang, Jun-Geun
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.6
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    • pp.91-107
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    • 2020
  • The purpose of this study is to explore quantitatively the success factors of YouTube's music cover channel. Along the process, constructing and testing the measurement for music cover channel's characteristics. The research constructed the measurement items based on results of qualitative studies. To perform the purposes the study suggest a research model which integrated the Post Acceptance Model with five music cover channel's characteristics based on the recent case studies. The five characteristics were contents, video, creator, interactivity, and publicity. The characteristics were integrated with Post Acceptance Model. After testing reliability and validity the research model was revised then, the research hypothesis was tested. The research results show: first, it was found that the content characteristics did not meet the expected value of users. Second, among the five factors of channel characteristics presented in creator's characteristics have the largest effect on user's value perception Third, in the factor analysis process, the content factor and the video were loaded on the same factor thus integrated as one factor. Fourth, satisfaction and intention for continual usage were also loaded on the same factor thus integrated as one factor. The research results suggest that music cover channel operators need to enhance the creator's attraction, communication with user, and publicity in various ways.

fs-laser Ablation and Optoperforation Threshold for PDMS Thin Film on $\mu$-channel (미세 유체 상 PDMS 고분자 필름의 펨토초 레이저 어블레이션 및 천공 임계치 연구)

  • Woo, Suk-Yi;Sidhu, M.S.;Yoon, Tae-Oh;Jeoung, Sae-Chae;Park, Il-Hong
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.2
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    • pp.29-33
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    • 2010
  • We have investigated fs-laser ablation as well as optoperforation threshold of PDMS (Polydimethylsiloxane) thin lid cover on ${\mu}$-channel with changing the flow medium from water to hemoglobin. The ablation threshold is found to be independent of both PDMS thin film thickness and flow medium, but the optoperforation threshold is dependent on the films thickness. The observation that the ablation process is well described with simple two-temperature model supposed that the cover lid PDMS of $\mu$-channel be processed with minimized thermal effects by fs-laser with low laser fluence.

Extraction of Snow Cover Area and Depth Using NOAA/AVHRR Images (NOAA/AVHRR 영상을 이용한 적설분포 및 적설심 추출)

  • Kang, Su-Man;Kwon, Hyung-Joong;Kim, Seong-Joon
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2005.10a
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    • pp.254-259
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    • 2005
  • The shape of a streamflow hydrograph is very much controlled by the area and depth of snow cover in mountain area. The purpose of this study is to suggest extraction methods for snow cover area and depth using NOAA/AVHRR images in Soyanggang watershed. Snow cover area maps ware derived form channel 1, 3, 4 images of NOAA/AVHRR based on threshold value. In order to extract snow cover depth, snow cover area maps were overlaid daily snow depth data form 7 meteorological observation stations. Snow cover area and depth was mapped for period of Dec. 2002 and Mar. 2003. For evaluating snowmelt changes, depletion curve was created using daily snow cover area in the same period. It is necessary to compare these results with observed data and check the applicability of the suggested method in snowmelt simulation.

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The Characteristics of Visible Reflectance and Infra Red Band over Snow Cover Area (적설역에서 나타나는 적외 휘도온도와 반사도 특성)

  • Yeom, Jong-Min;Han, Kyung-Soo;Lee, Ga-Lam
    • Korean Journal of Remote Sensing
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    • v.25 no.2
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    • pp.193-203
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    • 2009
  • Snow cover is one of the important parameters since it determines surface energy balance and its variation. To classify snow and cloud from satellite data is very important process when inferring land surface information. Generally, misclassified cloud and snow pixel can lead directly to error factor for retrieval of surface products from satellite data. Therefore, in this study, we perform algorithm for detecting snow cover area with remote sensing data. We just utilize visible reflectance, and infrared channels rather than using NDSI (Normalized Difference Snow Index) which is one of optimized methods to detect snow cover. Because COMS MI (Meteorological Imager) channels doesn't include near infra-red, which is used to produce NDSI. Detecting snow cover with visible channel is well performed over clear sky area, but it is difficult to discriminate snow cover from mixed cloudy pixels. To improve those detecting abilities, brightness temperature difference (BTD) between 11 and 3.7 is used for snow detection. BTD method shows improved results than using only visible channel.

A study on a transcription of pattern of the glass fiber reinforced laptom computer cover surface (유리섬유 강화 플라스틱 노트북 커버의 전사성에 관한 연구)

  • Kwak, Yong-Soo;Han, Seong-Ryeol
    • Design & Manufacturing
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    • v.10 no.3
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    • pp.39-45
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    • 2016
  • The purpose of this study is to build effective cooling circuit design in injection mold to improve glass fiber reinforced laptop computer cover plastics' transcription and gloss. Moldflow Insight and Ansys CFD CAE program used to verify efficiency and the experiment mold is precision machined and brazing soldered to make three-dimension cooling channel. The temperature of mold in injection test are fixed to $80^{\circ}C$ and $160^{\circ}C$. The result of this experiment is the improved surface quality of plastics with 85% improvement of transcription in high temperature mold.

A Study on a In-mold Packaging Process using Injection Molding (사출성형을 이용한 마이크로 채널의 패키징 공정에 관한 연구)

  • Lee, Kwan-Hee;Park, Duck-Soo;Yoon, Jae-Sung;Yoo, Yeong-Eun;Choi, Doo-Sun;Kim, Sun-Kyoung
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1821-1824
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    • 2008
  • A novel in-mold packaging process has been developed to manufacture devices with closed channels. In this unified process, fabrication of open channels and forming the rigid cover on top of them are sequentially integrated in the same mold. The entire process is comprised of two phases. In the first phase, the open channels are fabricated under an exquisitely controlled temperature and pressure using the conventional micro injection molding technology. In the second phase, the closed channels are fabricated by conducting the injection molding process using the molded structure with the open channels as a mold insert. As a result, the in-mold technology can eliminate the bonding processes such as heating, ultrasonic or chemical processes for cohesion between the channel and the cover, which have been required in conventional methods.

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Basic Investigation about Hydro-Geomorphologic and Vegetation Cover Changes on the Regulated River - A Case of the Downstream River of Andong Dam/Imha Dam on the Nakdong River (조절된 하천의 수문지형학적 변화와 식생 피복의 변화에 관한 기초 조사 - 낙동강 안동댐/임하댐 하류 하천 사례)

  • Woo, Hyo Seop;Rhee, Dong Sup;Ahn, Hong Kyu;Lee, Chang Seok
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.1335-1339
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    • 2004
  • A hydro-geomorphologic change in a sand bed channel reach and vegetation expansion by changes in the How regime is analyzed in this study. Field and aerial photo surveys, basic hydrological analysis about flow regime change due to two dams, Andong Dam and Imha Dam, on the upstream river and computer modeling are conducted. Two Dams in the study reach have obviously affected downstream channel in many ways including the bed particle coarsening, vegetation expansion on the sandbars and following river channel braiding. The phenomenon of no vegetation on the large point bar in front of Hahwe Village seems due to disturbance of the sandbar surface probably due to the cross flow in the meander reach during the flood. Another reason for no vegetation is that the sandbar on this reach has lower subsurface water lovels, as compared with the others in the up- and downstream of the reach where vegetation expanded, which would hinder vegetation from germinating and growing on the sandbar.

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The Analysis of GIS DB for the Evaluation of Turbid Water Considering Spatial Characteristics of River Channel (하천의 공간적 특성을 고려한 탁수평가 GIS DB 분석)

  • Park Jin-Hyeog;Lee Geun-Sang
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.1
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    • pp.19-26
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    • 2006
  • Andong and Imha reservoir adjoins each other, but turbid water shows too much different when it rains. The characteristics of geological rock in basin and agricultural area around river boundary are pointed out as the major reason of turbid water of Imha reservoir. This study analyzed rock type of topsoil layer using soil map by National Institute of Agricultural Science and Technology (NIAST). Among rock types, sedimentary rock affects on the occurrence of turbid water. In the analysis of sedimentary rock type, the distribution of sedimentary rock of Imha basin shows 1.87 times higher than that of Andong basin. Also, the distribution of sedimentary rock of Imha basin shows higher than that of Andong basin within 1,600m from river channel in according to the buffer zone of river boundary. And Agricultural area of Imha basin shows higher than that of Andong basin in analysis of land cover within 1,600 m from river channel. As this agricultural characteristics of Imha basin, cover management factor of Imha basin represents more higher that that of Andong basin.