• Title/Summary/Keyword: Tack time

Search Result 295, Processing Time 0.028 seconds

Heat Conduction of the Solidification Process in a Cylinder with Finite Thichness (유한두께를 가지는 원형관내의 응고과정의 열전도)

  • ;;Ro, Sung Tack
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.1 no.4
    • /
    • pp.196-202
    • /
    • 1977
  • The solidification process in a cylinder with finite thickness in studied by explicit finite difference method. The temperature distribution, the solidification front profile and the dischrged latent heat for the process are obtained. It is found that the solidification front profile is almost linear except in the vicinity of the initation of phase change. This result motivates us to use linear relations between the position of solidification and time for approximate calculations.

Clean mobile robot for wafer transfer (Wafer 낱장 반송용 이동 로봇의 개발)

  • 성학경;이성현;김성권
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.161-161
    • /
    • 2000
  • The clean mobile robot for wafer transfer is AGV that carry each wafer to each equipment. It has wafer handling technology, wafer ID recognition technology, position calibration technology using vision system, and anti-vibration technology. Wafer loading/unloading working accuracy is within ${\pm}$1mm, ${\pm}$3$^{\circ}$. By application of this AGV, we can reduce the manufacturing tack time and bring cost down of equipment.

  • PDF

A Qualitative Study of Five-Year-Old Children's Daily Activities at the Daycare Center (어린이집에서의 만5세 유아의 일과 분석)

  • Seo, Young-Hee;Lim, Jae-Tack;Kim, Eun-Ju
    • Korean Journal of Child Studies
    • /
    • v.30 no.4
    • /
    • pp.223-239
    • /
    • 2009
  • In order toidentify the daily activities of five-year-old children in a daycare center, the 23 children in "Yellow" class at "Yellow" Daycare Center were observed for seven months. Research was informed by a qualitative approach. Findings were that : children were rigidly attached to a time frame built into their daily classroom schedule, arranged by time and classroom space allotted to each unit. The meaning to the children was to be found in their "busyness;" they were very busy finalizing activities imposed by teachers within a short period of time. They spent most of their time moving about from one space to another within the classroom, and they played with their mostly artificial toys under rules set by the teacher.

  • PDF

Control of the Mobile Robot Navigation Using a New Time Sensor Fusion

  • Tack, Han-Ho;Kim, Chang-Geun;Kim, Myeong-Kyu
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.4 no.1
    • /
    • pp.23-28
    • /
    • 2004
  • This paper proposes a sensor-fusion technique where the data sets for the previous moments are properly transformed and fused into the current data sets to enable accurate measurement, such as, distance to an obstacle and location of the service robot itself. In the conventional fusion schemes, the measurement is dependent on the current data sets. As the results, more of sensors are required to measure a certain physical parameter or to improve the accuracy of the measurement. However, in this approach, instead of adding more sensors to the system, the temporal sequence of the data sets are stored and utilized for the measurement improvement. Theoretical basis is illustrated by examples and the effectiveness is proved through the simulations. Finally, the new space and time sensor fusion(STSF) scheme is applied to the control of a mobile robot in an unstructured environment as well as structured environment.

Effect of the Change of welding torch and piece arrangement by the 3-dimensional robot welding simulation (3차원 로봇용접 시뮬레이션에 의한 용접토치 및 부재배치의 변경에 따른 영향 평가)

  • 강현진;박주용;박현철;차태인;최동환
    • Proceedings of the KWS Conference
    • /
    • 2003.11a
    • /
    • pp.150-152
    • /
    • 2003
  • This simulation was carried out to estimate the process time and to improve the operation efficiency. The subassembly process consists of piece arrangement, tack welding, robot welding, manual welding and the robot welding of them was the focus of the simulation. Robot welding stage was analyzed by UML and IDEFø method, and then it was represented as the three-dimensional model(simulator) based on the analysis. The output of this simulation was the cycle time for one day's work. The cycle time for the different torch and the different piece arrangement was investigated by the 3-dimensional simulation.

  • PDF

A Synthetic Human Sensibility Assessment System based on Psycho-physiological Evaluation (심리·생리 평가를 기반으로 한 통합 감성평가 시스템)

  • Chung, Soon-Cheol;Tack, Gye-Rae;Yi, Jeong-Han;Min, Byung-Chan
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.31 no.2
    • /
    • pp.127-134
    • /
    • 2005
  • Human sensibility is assessed by measuring and analyzing various physiological signals in an objective way, or by analyzing adjectives chosen by the subjects in a subjective way. The present study aims at developing an integrated human sensibility assessment system that measures changes in a person's objective and subjective sensibility in real-time and analyzes them in an integrative way. The present system is composed of a real-time subjective sensibility assessment system, an automatic subjective sensibility assessment system and a real-time physiological signal measurement and analysis system for sensibility assessment, which are separated from one another. It can be utilized individually, or can be combined as a synthetic sensibility assessment system for comprehensive sensibility assessment.

Ink setting and back trap mottle

  • Kim, Byeong-Soo;Park, Jong-Ywal;Bousfield, Douglas W.
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
    • /
    • 2003.04a
    • /
    • pp.70-79
    • /
    • 2003
  • Paper coating can give smoothness surface and good printability to uncoated paper. Macro roughness of base paper would be decreasing its groove and grit in view of side. Nevertheless its improving effect for paper, some kind of problem is showing in the fine coated paper. Especially, back trap mottle is one of serious problems in printing with fine coated paper. Printers can not adjust conditions to overcome the problem. Also large amounts of paper can be rejected. There are many factors that influence back trap mottle. However it is not clear what the important parameters are in back trap mottle. Back trap mottle has some relationship with ink setting but good guidelines are not clear. Back trap mottle has been linked to non-uniform ink setting. We do not know how much variation in setting we can tolerate. Other mottle issues such as micro-picking and ink refusal are still common. This paper was prepared to identify correlation with ink setting and delta ink density obtained from experiment and then tried to find out some relationships with ink setting and back trap mottle. Basically fine calcium carbonate and ciay was used for main components and coarse calcium carbonate was mixed in two fine pigments to change its porosity and ink acceptance. Micro ink tack force at KRK printing tester was adapted to measure ink setting rate. KRK units were used for back trap mottle simulation and two printed samples were prepared to check delta ink density. Clay base coating has more fast ink setting time than calcium carbonate's though smoothness of clay was better than calcium carbonate. It could be explained by that clay has finer pore in its coating than calcium carbonate. DID(delta ink density) has shown a good correlation with ink setting time from micro ink tack. The total pore volume of coating layer did not match with ink setting and DID. From the results we might conclude coating that has fine pore size around 0.05 ${\mu}m$ can be exposed to high possibility of back trap mottle.

  • PDF