• Journal of Biosystems Engineering
• /
• v.11 no.2
• /
• pp.31-40
• /
• 1986

Cylindrical and conical types of grain-straw separation equipment which has a stationary crimped sieve drum with rotating inner rotor were constructed. The developed equipments were tested to investigate the characteristics of separating performance under various mechanical conditions and crop conditions. As increase of the inclination of equipment and decrease of pitch of cover vane, the grain recovery was increased while straw rejection was decreased. The grain recovery and overall efficiency were decreased as the rotor speed and feeding velocity were increased for both varieties of rice, moisture contents, and test equipments. Conical prototype equipment performed higher straw rejection, lower grain recovery, and lower power requirement. However, separation performance of conical type equipment was more widely varied with various test conditions compared to cylindrical one. The performance of both equipments showed relatively insensitive to crop feedrate and crop properties, such as variety, moisture content, and grain-to-straw ratio.

• Journal of Biosystems Engineering
• /
• v.17 no.4
• /
• pp.363-369
• /
• 1992

The aim of this study was to examine the blurring effects on performance of the experimental fruit grader in grading Fuji apples by size and coloration of the whole surface of individual apples. The grader consisted of a black/white image prcessing system, one camera, and utilized the algorithm developed for high speed sorting in the previous study. The results are summarized as follows : 1. With the algorithm developed in the previous study, it took 0.27~0.33 second in analyzing the size and coloration of an apple, and relative errors were within 3% for size and 1.3% for coloration. 2. The effect of blurring increased linearly with the conveying speed of apple and showed more significant effect on detection of coloration than on determining of size. 3. Considering the blurring effect, capacity of the experimental fruit grader was estimated to 7,500 apples per hour.

• Annual Conference of KIPS
• /
• 2015.04a
• /
• pp.941-944
• /
• 2015

저장 장치의 급속한 발전으로 인해 기존에 서비스할 수 없었던 개인 사용자를 위한 클라우드 서비스가 활성화되고 있다. 이 중 음악을 대상으로 하는 스트리밍 및 공유 서비스는 다양한 음악의 종류를 수용하기 위해 체계적인 분류를 필요로 한다. 기존의 분류체계는 단순히 작곡가나 업로더의 의견에 의해서 일방적으로 정해지기 때문에 사용자가 중심이 되는 클라우드 서비스에는 어울리지 않는다. 따라서 본 논문은 이와 같은 문제점을 해결하기 위해 사랑의 감정을 기준으로 새로운 분류체계를 제안한다. 자동적인 분류를 위해 데이터마이닝 기법을 접목시켰으며, 원활한 마이닝을 위해 오디오 음악 파일(raw data)을 정해진 크기로 자르고 feature extraction을 통해 오디오 음악 파일에 대한 전처리를 수행하였다. 이후 feature selection을 수행하기 위해 clustering을 이용해 유효한 중요도를 지나는 feature를 선별하였으며 선별된 feature를 토대로 SVN(Support Vector Machine)을 이용해 feature의 중요도에 대한 유효성을 검증함과 동시에 분류를 수행하여 감정을 기반으로 분류한 결과를 보였다.

• Resources Recycling
• /
• v.16 no.5
• /
• pp.57-64
• /
• 2007

Triboelectrostatic separation of mixed three kinds of plastics, PVC, PET and PMMA, in the range of similar gravity has been performed through a two-stage separation process. Polypropylene (PP) and high-impact polystyrene (HIPS) were found to be the most effective materials for a tribo-charger in the separation of PVC, PET and PMMA. In the 1st stage using the PP cyclone charger, PVC grade and recovery depended considerably on the air velocity (10 m/s), the relative humidity (<30%), the electric field (>200 kV/m) and the splitter position (+2 cm from the center) in the triboelelctrostatic separator unit. At an optimum condition a PVC grade of 99.6% and a recovery of 97.5% was achieved. In the 2nd stage using the HIPS cyclone charger, a PMMA grade of 98.3% and a recovery of 97.0% was obtained under the conditions of 10m/s air velocity, over 250 kV/m electric field, central splitter position and less than 40% relative humidity.

• Resources Recycling
• /
• v.16 no.5
• /
• pp.51-56
• /
• 2007

Plastics are widely used in everyday life as very useful material. In Korea, about 4 million tons of plastic wastes are generated annually. However, recycling ratio is below 30%, and most of plastic wastes are disposed by landfill and incineration. Hence, the development of material separation technique that can recycle plastic wastes is a necessary situation. In this study, Triboelectrostatic separation for recovery of PET from final plastic wastes obtained from the sink product after wet-type gravity separation has been carried out. In the charging properties, the charge polarity and charge density of PET and PVC were very effective with the tirbo-charger made of PP and HDPE with the decrease in relative humidity. In material separation using HDPE cyclone charger, a PET grade of 96.80% and a recovery of 85.0% were achieved at 30 kV and the splitter position -2cm from the center. In order to obtain PET grade of 98.5%, PET recovery should be sacrificed by 24% with moving the splitter from the center to -6cm position.

• Resources Recycling
• /
• v.25 no.1
• /
• pp.24-30
• /
• 2016

The study to obtain tantalum concentration from electronic components (ECs) on Printed circuit board assembly (PCBA) of laptop was conducted. Electronic components on laptop PCBA were detached from boards by using self-developed experimental apparatus. The detached electronic components were sieved and 93.2 wt.% of tantalum capacitors were concentrated from the size interval from 2.80 mm to 6.35 mm. The tantalum capacitors were pulverized by hammer mill and electrodes (anode and cathode) were removed from the grinding products by using magnetic separators under the magnetic force of 300 Gauss. Finally, tantalum concentrate was concentrated from the magnetic separator products by using Knelson concentrator, and the maximum efficiency of 76.9% was achieved under the operating condition of bowl rotating speed of 200 rpm, and fluidizing water flowrate of 7 L/min. The grade and recovery of Ta concentrate under the condition were 81.1% and 78.8%, respectively.

• Resources Recycling
• /
• v.21 no.5
• /
• pp.44-49
• /
• 2012

In this study, the sonication method was applied to remove ink from old newspaper(ONP) using flotation. Results indicated increased whiteness and effective residual ink concentration (ERIC) with longer disintegration. Therefore 58% of whiteness and 182.9 ppm ERIC were obtained for 30 minutes of disintegration time without the change in yield. Longer disintegration than 30 minutes had no effects on whiteness without the application of ultra-sonication. On the other hand, higher than 58% of whiteness was achieved in 2 minutes of disintegration when the ultra-sonication was applied. The highest whiteness (59.32 %) was obtained by applying sonication for 20 minutes and froth flotation with kerosene as a collector under the alkaline condition (pH 11).

• Resources Recycling
• /
• v.13 no.1
• /
• pp.39-46
• /
• 2004

Triboelectrostatic separation process is a technology that different particles charged after contact and rubbing different materials are separated in a high electric field. This technology has an advantage in that it can be used for separating non-conducting materials such as plastics unlike other electrostatic separation processes. There are two objectives in this study. One is to develop an effective continuous tribo-electrostatic separation process. The other is to apply the developed device for the separation of mixed plastics. Results show that almost all tested plastics reaches over 95% in yield and grade after separation.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2001.11a
• /
• pp.30-34
• /
• 2001

본 논문에서는 근거리에 놓여있는 노트북, 휴대폰, PDA, 혜드셋 등 각종 이동 가능한 장치들을 하나의 무선네트워크로 연결할 수 있는 블루투스의 베이스밴드 시스템 프로토콜 기능을 분석하고 설계하였다. 즉, 전체적인 논리 기능구조를 설계한 후 하드웨어로 구현될 패킷생성 블록, HEC와 CRC 기능블륵, Whitening/Dewhitening 기능블록, FEC 기능블록, 입출력 블록(TX, RX 루틴), 클럭 생성 기능블록, 주파수 선별 기능블록, 오디오 기능블록 그리고, 패킷 제어 블록들의 처리절차를 Verilog HDL 코드로 설계 및 검증하였다.

• Proceedings of the KAIS Fall Conference
• /
• 2008.11a
• /
• pp.160-163
• /
• 2008

This study developed selecting equipment for damage of street lamp circuit used by current transform and diode. To develop this system, current check used current transform and indication system used LED device. As faulted, current of street lamp circuit change with fault decivce. This chage of current detected and indicated by selecting equipment