• Title, Summary, Keyword: Fine

Search Result 11,867, Processing Time 0.068 seconds

Korean fine blanking industries and technology development (국내 파인블랭킹 산업 현황과 기술 개발)

  • Kim, Jong-Deok
    • Journal of the Korea Society of Die & Mold Engineering
    • /
    • v.9 no.1
    • /
    • pp.5-8
    • /
    • 2015
  • The company Daewoo Precision Industries imported fine blanking press of 40 tons from Switzerland with fine blanking tool in order to produce the fuse part of bomb in 1978 at first in Korea. About 1985 the first fine blanking tool for producing the door lock parts was manufactured in the company Gold Star (now LG). And then this technology was grown up with the growth of automobile industries in Korea. Now 31 companies are closely related to the fine blanking technology and there are total 146 fine blanking presses in Korea. The developments of fine blanking technology in industries have been oriented to the production of precise fine blanking parts, the reduction of die roll height on fine blanking parts, the production of complex fine blanking parts with progressive fine blanking tool including forming and forging technology, the production of high-strength steel fine blanking parts and so on. Some R&D activities in KITECH were introduced.

  • PDF

A Study on the Design and Implementation of Fine Dust Measurement LED Using Drone

  • Park, Jong-Youel;Ko, Chang-Bae
    • International Journal of Internet, Broadcasting and Communication
    • /
    • v.12 no.4
    • /
    • pp.48-54
    • /
    • 2020
  • Researchers recognized air pollution changes causing diseases and difficulties in living due to environmental pollution following various human activities, and have studied how to avoid fine dust harmful to the human respiratory system to be healthy. To this end, Arduino is used to equip fine dust level sensors in drones to measure the fine dust levels, visualize the measurements with LED indicator colors depending on the measurements to inform users of the danger of fine dust, and use the benefits of drones to specify dangerous fine dust zones and measure the fine dust levels. Users can see the changes depending on the fine dust levels in real time with the LED indicators. This will contributes to measuring fine dust levels easily in dangerous areas. Mission Planner (ArduPilot) is used to set up the GPS of drone, and store the data from the dust sensor as contents. This study aims to establish a method for improving the environment to measure fine dust levels with drones with LED indicators for fine dust, and reduce fine dust.

A Robust Fine Seek Controller Design Method Based on the Estimation of Velocity Disturbance

  • Lee, Moon-Noh;Shin, Jin-Ho;Kim, Seong-Woo;Lee, Jong-Min;Jin, Kyoung-Bog
    • International Journal of Control, Automation, and Systems
    • /
    • v.5 no.3
    • /
    • pp.243-250
    • /
    • 2007
  • This paper presents a systematic method of estimating a velocity disturbance occurring in the fine seek control system of an optical disk drive. A fine seek loop gain adjustment algorithm is introduced to accurately estimate the velocity disturbance in spite of the uncertainties of the fine actuator. The velocity disturbance can be estimated from a measurable velocity, a fine seek controller output, and a compensated fine actuator model. A robust fine seek controller can be designed by considering a minimum fine seek open-loop gain, calculated by the estimated velocity disturbance. The proposed controller design method is applied to the fine seek control system of a DVD rewritable drive and is evaluated through the experimental results.

Development of Acoustic Emission Monitoring System for Fine Machining - Application to Cutting State Monitoring in a Fine Fixed-abrasive Machining - (미세 음향방출 감시장치 개발 - 고정도 미세입자 가공상태 감시에의 적용 -)

  • Kim Hwa Young;Ahn Jung Hwan;Kim Sung Ryul
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.22 no.6
    • /
    • pp.109-117
    • /
    • 2005
  • In case of fine machining processes, the cutting state monitoring by a skilled operator is impossible because the physical changes generated during fine machining are very weak. To realize the high efficient and precise fine machining, it is necessary to develop the sensor based monitoring system which is able to detect the fine changes of cutting state. In this paper, the fine acoustic emission monitoring system is developed to monitor the state of the fine machining process. The developed system consists of the AE sensor and the AE signal processing unit. And this has the high-sensitivity and bandwidth which can detect fine AE signal generated during fine machining process. In order to investigate the feasibility of the developed system, evaluation experiments were performed in the fine fixed-abrasive machining processes such as polishing and glass ferrule slicing. Experimental results show that the developed monitoring system possesses an excellent real-time monitoring capability at fine machining processes.

The Properties of Mortar Mixtures Blended with Natural, Crushed, and Recycled Fine Aggregates for Building Construction Materials

  • Yu, Myoung-Youl;Lee, Jae-Yong;Chung, Chul-Woo
    • Journal of the Korea Institute of Building Construction
    • /
    • v.12 no.1
    • /
    • pp.73-86
    • /
    • 2012
  • In this research, the possible applicability of mixture blended with natural, crushed, and recycled fine aggregate are discussed. The fresh and hardened properties of mortar using blended fine aggregates are monitored depending on various blending ratio of fine aggregates. Newly developed ternary diagram was also utilized for better interpretation of the data. It was found that air content increased and unit weight decreased as recycled fine aggregate content increased. With moisture type processing of recycled fine aggregate, the mortar flow was not negatively affected by increase in the recycled fine aggregate content. The ternary diagram is found to be an effective graphical presentation tool that can be used for the quality evaluation of mortar using blended fine aggregate.

A Study on the Recycled Fine Aggregate and Properties of Mortar by the Acid Treatment (산처리에 의한 순환잔골재의 품질과 모르타르의 특성에 관한 연구)

  • Kim Ha-Suk;Sun Joung-Soo;Kawg Eun-Gu;Han Ki-Suk;Lee Do-Heune;Kim Jin-Man
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • /
    • pp.81-84
    • /
    • 2006
  • This study is intended for how to utilize the recycled fine aggregate which is produced by concrete wastes. It analyzes the quality of the fine aggregate which is reproduced through the acid treatment process, and comprehends the characteristics of mortar using the recycled fine aggregate to review whether it can be put to practical use for concrete. The conclusion of the study are as follows 1. The recycled fine aggregate through the acid treat shows the low rate of absorption and high density. 2. Compared to the mortar made from acid liquid precipitated recycled fine aggregate, using nature water precipitated one reduces the flow. 3. The compressive strength of mortar using recycled fine aggregate tends to be reduced according to the kind of precipitated water. Based on the above results, the recycled fine aggregate through the acid treatment process satisfies the quality standards of the first-grade recycled fine aggregate of KS F 2573 (recycled fine aggregate for concrete) but it is concluded that the recycled fine aggregate through the acid treatment process can not used as fine aggregate used concrete because it has destructive characteristics when the mortar is produced

  • PDF

Physical Properties of Fine Dust Adsorption Matrix using Powder Activate Carbon (분말활성탄을 활용한 미세먼지 흡착형 경화체의 물리적 특성)

  • Lee, Won-Gyu;Kim, Yeon-Ho;Kyoung, In-Soo;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • /
    • pp.172-173
    • /
    • 2019
  • As the damage to fine dust increased, the Republic of Korea designated fine dust as a social disaster. The composition of the fine dust is composed of carbon, sulfate, nitrate, ammonium and minerals. The cause of fine dust is naturally generated by dirt, pollen, etc. In addition, there are artificial causes such as gaseous vehicle exhaust gas emitted from the use of fossil fuel. When fine dust enters the human body through breathing, it causes various respiratory diseases and skin diseases. In IARC, fine dust was designated as a carcinogen group 1. In this research, we tried to adsorb fine dust by physical adsorption using powdered activate carbon. Powdered activate carbon is a powdered activated carbon activated in a carbonized state. Porous material with high specific surface area and low density. Experimental items were tested for density, water absorption, and fine dust concentration according to the PAC addition ratio. Basic experiments were carried out to fabricate the fine dust adsorption matrix.

  • PDF

Strength Characteristics of Unsaturated Polyester Resin Mortar using Recycled Fine Aggregates

  • Kim, Wha-Jung;Choi, Young-Jun;Jun, Joo-Ho;Kim, Yong-Bae
    • KCI Concrete Journal
    • /
    • v.11 no.3
    • /
    • pp.89-97
    • /
    • 1999
  • The purpose of this research is to investigate the utilization of recycled fine aggregates as a material to apply to a building finished walls or as a decorating material in combination with a polymer. The strengths of two resin mortars using recycled fine aggregates and natural fine aggregates was made. In order to improve the workability and the strength of the resin mortar with recycled fine aggregates, partial replacement of recycled fine aggregates with natural ones was made with the application of various type of fillers. The results, it show that the compressive strength and flexural strength of resin mortar using the recycled fine aggregates were about 70% to 100% of those of resin mortar using natural fine aggregates. It was enough to assure the utilization of the recycled fine aggregates as a material for the production of resin mortar. From the result of partial replacement of recycled fine aggregates with natural ones, the compressive strength was Increased from 5% to 15% and the flexural strength was much as 5% to 20% as a result of 70% substitution It was also found that the use of garnet powder shows a similar tendency in the compressive strength and slag powder does in the flexural strength and tensile strength.

  • PDF