• 펄프종이기술
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• 제48권3호
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• pp.14-22
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• 2016

Pulping is a stage that can change fibrous raw materials into pumpable slurry. Recovered paper can be defibrated to individual fibers by shear stress generated by rotation of a rotor and water. Disintegration of recovered paper is more complicated than that of chemical pulp. When disintegration of recovered paper is poor, screening and cleaning efficiency will be worse and properties of paper will also be deteriorated. Therefore, pulping is an important treatment for improvement of availability of recovered paper and process runnability. In this study, degrees of disintegration of KOCC obtained from a linerboard mill was analyzed with a pilot-scale screen. Flake removal of KOCC slurry was performed by a pilot screen. Simple pumping action gave a positive effect on disintegration of KOCC. After pumping for 10 minutes, paper strength increased without the change of water retention value and fibrillation of KOCC slurry. This phenomena can be explained by modification of hornified surface of KOCC fibers by shear stress generated by pumping. Consequently, disintegration efficiency of KOCC can be enhanced by control of retention time at pulper or an agitation power at chests of papermaking process.

• 펄프종이기술
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• 제47권4호
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• pp.66-75
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• 2015

Disposable diaper waste is consisted of plastic, fiber, and SAP (Super Absorbent Polymer). They are valuable to be used as raw materials of other products including plastic blocks and pulp mold. Nevertheless, disposable diaper waste have been disposed by landfill and incineration without recycling. Due to strict environmental regulations it is necessary to develop fractionation technique to recycle the disposable diaper waste. In this study the fractionation technique using pilot-scale stock preparation units was investigated. Process for separation of plastic and fibers from disposable diaper waste was composed by the combination of pilot-scale pulper, drum screen, screen and cleaner. Recovery rate of plastics and fiber was checked according to the various operating conditions. In drum screen, recovery rate of plastic was high when the cut size of disposable diaper waste was $5cm{\times}5cm$. The highest recovery rate of fiber was achieved with 0.3 mm slot screen. It is important to control the neutral state of SAP for improvement of recovery rate of fiber since SAP can be swelled easily in water. Therefore SAP can be controlled efficiently by the addition of calcium chloride into the pulper. Consequently recovery rates of plastics and fibers were over 90 and 80% under the optimum pilot operating conditions.

• 대한환경공학회지
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• 제28권7호
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• pp.697-703
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• 2006

물 재이용 목적으로 설계한 pilot scale의 하수 처리공정에서 배출되는 방류수 중 내분비계 장애물질을 GC/MS로 분석하였고, 처리 공정별로 제거율을 비교하였다. 각 처리 공정별 방류수에서 nonylphenol이 주로 검출되었고, 평균 $0.36{\sim}0.94$ ${\mu}g/L$으로 높게 검출되었으나, E2와 EE2는 처리수에서 정량 이하로 검출되었다. 내분비계 장애물질은 처리 공정별로 $50{\sim}100%$의 제거율을 보여주었다. E-screen assay에 의해 얻어진 양-반응 곡선에서 E2의 EC50값은 $9.0{\times}10^{-3}$ M로 bisphenol A와 p-octylphenol의 EC50값인 $2.736{\times}10^{-5}$ M, $9.760{\times}10^{-6}$ M에 비해 매우 높았다. 이는 알킬페놀류가 E2에 대한 상대적인 에스트로겐 활성도가 매우 낮음을 보여주었다. 환경 호르몬 농도와 이 물질의 상대적인 에스트로겐 활성도에 근거하여 계산된 에스트로겐 활성도(ng-EEQ/L)는 E-screen assay에 의해 실측한 총 에스트로겐 활성도(ng-EEQ/L)에 비해 평균 2배의 높은 활성도를 보여 주었다. 각 처리 공정별 방류수의 에스트로겐 활성도는 1 ng-EEQ/L 이하의 매우 낮은 활성도를 보여주었다.

• 펄프종이기술
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• 제42권1호
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• pp.20-25
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• 2010

Fractionation effects of the slot-type and the hole-type screens of mutifractors were studied using a pilot multifractor. We used a slot screen of 0.15 mm, and two hole screens of 1.0 and 2.0 mm, respectively, in the study. We found hole-type screens were more effective for fractionation of fiber furnishes according to their fiber lengths. Slot-type screen was more effective to remove the shives from the accepted fiber furnishes. There existed a high regression coefficient between the fiber length differences and the freeness differences of the accepted and the rejected fiber furnishes.

• 펄프종이기술
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• 제40권5호
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• pp.27-35
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• 2008

In order to determine the most appropriate recycling line to treat old corrugated container (OCC) to substitute unbleached kraft pulp (UKP) for the manufacture of kraft paper, three recycling lines were evaluated in pilot scale tests. The recycling line consisting of kneading, flotation, washing, dispersion and screening steps was able to produce pulp with acceptable appearance. Kneading was shown to be more efficient treatment to reduce specks than dispersion. In addition, 0.2 mm slot screen was very effective to remove specks. Severe damages on fiber morphology such as shortening of fiber and formation of fines were not observed during mechanical treatments such as kneading and dispersion. Most of strength properties of the kraft paper produced with the recycled pulp were found to be slightly increased after treated in the recycling lines.

• 전기학회논문지
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• 제67권10호
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• pp.1395-1400
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• 2018

EO TGP(Electro-Optical Targeting Pod) is an optical tracking system which has various functions such as target tracking and image stabilization and LOS(Line of Sight) change. Especially, it is very important to move the LOS into a interest point for joystick command. When pilot move joystick in order to observe different scene, EO TGP gimbals should be operated properly. Generally, most EOTS just operate corresponding gimbal for joystick command. For example, if pilot input horizontal command in order to observe right hand screen, it just drive azimuth gimbal at any position. But in the screen, the image dosen't move in a horizontal direction because gimbal structure is Euler angle. And image rotation is occurred by elevation gimbal angle. So we need to move Pitch gimbal. So in the paper, we designed LOS moving algorithm which convert LOS command to gimbal velocity command to move LOS properly. We modeled a differential kinematic equation and then change the joystick command into velocity command of gimbals. This algorithm generate velocity command of each gimbal for same horizontal direction command. Finally, we verified performance through MATLAB/Simulink.

• Child Health Nursing Research
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• 제12권2호
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• pp.260-267
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• 2006

Purpose: This pilot study was to develop Korean version of CDI(The Child Development Inventory) and assess the validation and reliability on K-CDI. Method: The K-CDI is assessed by parent-report method that has designed to screen children developmental functioning on 12 months to 6.5 years of age /or older children who are judged to be functioning in the one to six-year range. The inventory assesses areas of child development in the social, self-help, motor, language, letter and number skills. also, it includes various symptoms and behavior problems that young children may have. Participants were 130 children and their mothers who has lived in Seoul or Gyounggi-Do. Data was analyzed on the ratio of item response, Pearson's correlation, and Cronbach alpha. Results: 270 items with 8 sub-developmental realms were confirmed the reliabilities and validity on Korean children. Total 300 items were selected for restandardization. There was a significant correlation between the score of Social Maturity Scale and K-CDI. The corrlation coefficient alpha was .98. Conclusion: This study indicated that CDI is applicable in the clinical and early childhood educational setting for developmental assessment in Korea.

• 한국항해항만학회지
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• 제36권7호
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• pp.571-575
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• 2012

Berthing and unberthing maneuver is essential work for marine pilots and securing the safety against risks during the maneuver is more important than anything else. Moreover, the maneuvering environment in ports and harbors has changed rapidly and got worse due to development of a new port, the advent of a new type or large-sized ship, and the rapid increase in harbor traffic. As one of measures taken to cope with such changes in the maneuvering environment and for each pilot to improve his own maneuvering ability, this paper developed laptop-based ship-handling simulator which is readily available anytime and anywhere. This paper is to develop a conning display for ship's maneuvering and electronic chart based display widely used nowadays to represent a model ship's movement. The displays were arranged appropriately considering pilot age, easy handling by mouse, using a maximum screen, proper arrangement of rudder, engine, thruster, tug etc and representation of information. Up to now thirteen (13) model ships were developed based on real-ship, whose mathematical model is Japanese MMG & pilots' low speed maneuver.

• 교육녹색환경연구
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• 제14권2호
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• pp.37-44
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• 2015

2005년 "학교폭력 및 예방에 관한 법률"이 제정되면서 학교에 CCTV가 설치 운영되고 있다. 하지만 실제 학교현장에서는 CCTV 설치보다는 운영상의 모니터링 환경에 있어 문제점들이 발생하고 있다. 본 연구는 상기 문제점들 중 가장 큰 문제점인 CCTV 감시환경에 따른 적합한 모니터의 크기를 산정할 수 있는 모델을 제시함에 있다. 이를 위해 첫째, 선행연구를 통해 CCTV의 기본적 원리 및 적정 모니터링에 대한 기준을 분석한다. 둘째, 실태조사를 실시하여 실제 학교현장에서의 CCTV 모니터링 운영현황을 분석한다. 셋째, 국내 경비인력의 일반적인 시력을 기준으로 CCTV 사양 등에 따른 모니터의 출력크기를 산정할 수 있는 산정식과 적정한 모니터 크기를 산정할 수 있는 모델을 제시한다. 결론적으로 대부분의 학교현장에 설치된 CCTV를 고려하여 4개 분할화면의 모니터링을 적용하기 위해서는 최소 27인치의 모니터가 필요하다는 결과를 도출하였다.

• 한국농촌건축학회논문집
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• 제21권3호
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• pp.17-24
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• 2019

This study aimed to develop a mobile separating and sorting device for discharge sites to separate and sort mixed construction waste generated in small and medium scale in small provincial cities into inorganic materials and combustible materials. The study results can be summarized as follows: 1) As a result of analyzing the existing domestic technology for the separating and sorting mixed construction waste, a device sorting the waste by fusing the vibration screen, disc screen, air blowing methods and the separating and sorting the combustible waste is applied in Korea. 2) In foreign countries, the air blowing, screen, gravity sorters are used for separating and sorting combustible waste in the same way as in Korea. Especially German T Company suggests a construction waste separating and sorting system using an optical sorter. 3) As for the test device for separating and sorting mixed construction waste to be buried in landfill, the processing capacity was set as 16 tons per day. 4) For separating and sorting inorganic materials by granularity, this study set a trommel with two types of diameter as a basic. To operate the mobile all-in-one system, the device is designed to locate a conveyor, a combustible waste conveying device, inside of the trommel. 5) The device is designed in a mobile mode under the concept of primary separating and sorting device, and it can be transported using a 2.5-ton truck minimum. The diameter and length of the trommel are designed to be within 1500mm and 3000mm, respectively. In a further study, an optimized separating and sorting technology is planned to be presented through an experimental study for processing efficiency analysis at the mixed construction waste site by manufacturing the pilot experiment facility reflecting the design elements in the result of this study.