• 한국입자에어로졸학회지
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• 제9권3호
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• pp.139-147
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• 2013

The performances of indoor air cleaners including particle cleaning capacity and collection efficiency are usually tested at the condition of the maximum air flow rate of the air cleaners. However, the power consumption of the air cleaners is highly dependent on the air flow rate of the individual air cleaners. Therefore, there seems to be an optimized air flow rate for the air cleaning capacity considering power consumption. In this study, clean air delivery rate(or standard useful area as suggested room size) and power consumption have been investigated for different maximum air flow rates of 15 air cleaners and then compared those for different air flow rate modes of the individual 5 air cleaners selected from the 15 cleaners. For the maximum air flow rate conditions of 15 air cleansers, the power consumption per unit area was less related to the maximum air flow rate. However, for the different air flow rate modes of the selected 5 air cleaners, the lower power consumption per unit area was corresponding to the lower air flow rate mode of the individual air cleaners. When considering the operation time to the desired particle concentrations, there was an optimized one in the medium air flow rate modes for the individual air cleaners. Therefore, not only the maximum air flow rate but also lower air flow rates of individual air cleaners should be considered for estimating air cleaning capacity based on energy consumption per unit area.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.195-196
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• 2011

Recently, the number of high-rise buildings has been on the rise, which has meant that maintenance cost has increased by two and three times, along with the increase in the construction cost. It is suggested that the use of an auto-cleaning robot could increase the productivity and safety of cleaning work, which is mostly done outside of a building. In particular, the guide rail on a high-rise building could be useful in this capacity, as it has the advantage of not being significantly influenced by factors of the external environment, including wind pressure. For this reason, this research is preliminary research into a cleaning automation for a high-rise building, and aims to draw up a scenario for the vertically moving robot.

• 한국산학기술학회논문지
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• 제11권3호
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• pp.1016-1022
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• 2010

액상 중유 연료를 사용하는 고용량 증기 보일러에서 발생되어 연소기기 내부에 침적되는 슈트, 슬래그, 크랭커, 회분, 산화물의 on-line 세정을 위한 세정제 제조에 대한 연구를 수행하였다. 액상 중유 연료를 사용하는 보일러 및 가열로에 생성되는 슈트, 슬래그, 크랭커, 회분, 산화물을 제거하는 기존 기술은 보일러 및 가열로의 가동 중단 후 작업자들에 의한 기계적인 처리를 통하여 침적물을 제거하는 기술을 사용하고 있다. 기존 기술을 대치할 수 있고 보일러의 중단이 없는 상태에서 침적물을 세정할 수 있는 세정제의 최적 조성을 도출하였다. 질산암모늄과 질산마그네슘의 혼합물이 주 세정제로 도출되었으며, 각종 전이금속 화합물에 의한 영향을 영향을 연구하여, 세정에 의한 부식을 방지할 수 있으며, 연소효율의 증대를 얻을 수 있는 전이금속화합불 첨가제를 도출하였다.

• Journal of Biosystems Engineering
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• 제33권4호
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• pp.230-238
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• 2008

Mechanization such as machine harvesting, precleaning, drying and cleaning for rapeseed harvested with high moisture content should be accomplished for biodiesel production. In addition, machine drying and cleaning is inevitable in the mechanization of work, just because rice should be transplanted right after harvesting rapeseed in Korea. Particularly, early harvested rapeseed with the combine have high moisture content and undesirable materials such as stalks and stones which make drying-process difficult and lower the efficiency of drying. Therefore, this study was conducted to develop precleaner and cleaner which could remove foreign substances from harvested rapeseeds. The precleaner consists of throw-in hopper, conveyor, feeding hopper, two precleaning sieves and discharging sections. Precleaning capacity was 1,505 kg/hr in shaking frequency of 370 cpm (cycles per minute) and tilt angles of between $5^{\circ}$ and $7^{\circ}$. The efficiency of precleaning was between 90.9% and 91.5%. The cleaner consists of feeding, shaking, blowing, cleaning and discharging sections. Cleaning performance was 435.4kg/hr in the number of rocking motions of 475 cpm and tilt angle of $10^{\circ}$. The ratios of cleaning, foreign substances and loss were 96.5%, 3.5% and 0.2%, respectively.

• 대한금속재료학회지
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• 제50권5호
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• pp.353-360
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• 2012

The corrosion product of archaeological iron objects is supposed to be removed because it causes re-corrosion. So far it is removed by scapel and sand blaster but they depend on the skill and experience of a conservator and the glass-dust of the sand blaster is harmful to humans. Therefore this study applies a laser cleaning system which is used in various industrial cleaning processes, to remove corrosion product from archaeological iron objects. In addition, this work studies the alternation of corrosion product after laser irradiation, which evaluates the reliability of the laser cleaning system. Optical microscopy, SEM-EDS, XRD, Raman have been used to observe and analyse the surface of the objects. The results show the capacity of laser cleaning some corrosion product, but blackening appears with increasing pulses and laser energy, and some corrosion products, goethite and hematite, are partially altered to magnetite. These problems, blackening and alternation of corrosion product, should be solved by further studies which find the optimal laser irradiation condition and use a wetting agent.

• 청정기술
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• 제16권2호
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• pp.103-116
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• 2010

평면 판넬 디스플레이(FPD)산업 중 액정표시장치(LCD) panel 시장은 계속 성장하고 있으며, 대형화와 생산은 해마다 증가하고 생산기술은 향상되고 있다. FPD의 제조공정은 고도의 청정성이 요구되는 공정으로 제조공정 중 세정공정이 30~40%를 차지할 정도로 기술적 생산성 측면에서 매우 중요하다. 그 중 액정주입 후 잔류하는 액정은 미세갭에 잔류하여 제거하기 매우 어렵다. 본 연구에서는 대체세정제의 원료로 많이 이용되고 있는 glycol ether계 용제, glycol dimethyl ether계 용제, 그리고 비이온계면활성제를 사용하여 우수한 세정력, 린스력, 침투력을 갖고 배선에 영향을 주는 이온함량을 최소화한 수계세정제를 개발하여 액정주입 후에 사용되는 panel의 액정 세척에 적용해 보았다. 이에 따라 배합성분들의 혼합비에 따른 세정제의 물성, 세정 효율 및 헹굼성을 측정하여 보았다. 실험 결과에 따르면, 배합세정제는 기존의 세정제보다 높은 습윤지수와 높은 운점을 보였다. 그리고 세정제의 주용제의 구조변화와 오염물로서 액정의 종류에 따라 세정효율이 영향을 미치고 있음이 확인되었다. 또한 최적의 배합세정제는 기존의 세정제에 비하여 동등이상의 세정력을 보여주었고 헹굼성능도 훨씬 우수하였다.

• Nuclear Engineering and Technology
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• 제51권2호
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• pp.641-645
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• 2019

Experimental equipment for studying the sorption properties of iodine sorbents using radioactive methyliodide has been developed. The sorption capacity index ${\alpha}$ is proposed as a criterion parameter for assessing the quality of impregnated activated charcoals. It was found that this parameter does not depend on the dynamic conditions during the sorbent test. It was shown that values of the sorption capacity index allow to recommend iodine sorbents for industrial gas cleaning processes.

• Journal of Biosystems Engineering
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• 제19권1호
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• pp.22-32
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• 1994

The combine harvester is considered as an important but complicated and costly machine. The appropriate size of combine has to be developed to use efficiently in Korea. But the combine is such a complicated machine that a complete design model to develop a new type is impossible without understanding the relationship between each factor. The combine capacity is generally limited by the cleaning shoe performance. So a design model for a cleaning shoe has to be developed first for the complete combine design. The objective of this research was to develop a cleaning model of head-feeding combine to predict grain separation from chaff and broken straw on a sieve. A developed physically based model can explain the situation which can happen during separation process. A test apparatus based on the field going machine was developed. The test materials were paddy rice and barley. The data obtained were analyzed by the hand and the video camera. The developed model was verified as an adequate model through the test with $R^2$ of 0.934 and 0.837. The model can be used to evaluate design and operation alternatives of combine and also applied to the automatic control of separation unit of combine with a loss monitering sensors.

• 반도체디스플레이기술학회지
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• 제7권3호
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• pp.17-21
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• 2008

Application of flash memory in mobile and ubiquitous related devices is rapidly being increased due to its low price and high performance. In addition, some notebook computers currently come out into market with a SSD(Solid State Disk) instead of hard-drive based storage system. Regarding this trend, applications need to increase the storage capacity using multiple flash memory chips for larger capacity sooner or later. Flash memory based storage subsystem should resolve the performance bottleneck for writing in perspective of speed and lifetime according to its physical property. In order to make flash memory storage work with tangible performance, reclaiming of invalid regions needs to be controlled in a particular manner to decrease the number of erasures and to distribute the erasures uniformly over the whole memory space as much as possible. In this paper, we study the performance of flash memory recycling algorithms and demonstrate that the proposed algorithm shows acceptable performance for flash memory storage with multiple chips. The proposed cleaning method partitions the memory space into candidate memory regions, to be reclaimed as free, by utilizing threshold values. The proposed algorithm handles the storage system in multi-layered style. The impact of the proposed policies is evaluated through a number of experiments.

• 한국공간구조학회논문집
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• 제8권2호
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• pp.55-62
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• 2008

막 구조는 형태의 다양성, 막의 가벼움과 내구성, 투광성 및 균질성 때문에 현대 건축물에 다용하게 사용되어 새로운 건축세계를 열어가고 있다. 본 논문은 대공간 건축 구조물에 주로 사용되는 유리섬유 막 재료의 역학적 특성에 대한 연구이다. 현재 주로 사용되는 건축용 막 재료의 종류에는 PVC, PVF, PVDF, PTFE, ETFE 막재들이 있다. 본 연구에서는 이러한 건축용 막재료에 대한 역학적 시험 방법을 정립하고, PTFE 코팅 유리섬유 막재에 대한 인장강도, 인열강도 및 반복하중 시험 등을 실시하여 건축용 막 재료의 역학적 특성을 분석하고자 한다.