• 펄프종이기술
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• 제44권4호
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• pp.1-7
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• 2012

The increase of OCC solid content after wet pressing will save drying energy greatly. We applied spacers, which used to increase draining rate and bulk in fiber furnishes, to increase the OCC solid contents. MDF fibers (fibers for making medium density fiberboard) and diatomaceous earth were used as spacers, and added 10% by weight to the OCC fiber furnish. Application of high wet pressing pressure to the mixed furnish of spacers and refined OCC did not deteriorate bulk and drainage rate, but their solid contents were increased to 0.5-1.5% without loss of compressive strength when compared to those of unrefined OCC, which is the furnish normally used for mill commercial practice. It is believed that the spacers caused the rate of solid content increase faster in the mixed furnish with OCC at high wet pressing pressure area than the unrefined OCC furnish did. Little amount of starch addition (0.5%) to the spacers helped to keep the strength properties.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.31-32
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• 2010

In our previous reports [1-3], electron transport for the switching and memory devices using alkyl thiol-tethered Ru-terpyridine complex compounds with metal-insulator-metal crossbar structure has been presented. On the other hand, among organic memory devices, a memory based on the OFET is attractive because of its nondestructive readout and single transistor applications. Several attempts at nonvolatile organic memories involve electrets, which are chargeable dielectrics. However, these devices still do not sufficiently satisfy the criteria demanded in order to compete with other types of memory devices, and the electrets are generally limited to polymer materials. Until now, there is no report on nonvolatile organic electrets using nano-interfaced organic monomer layer as a dielectric material even though the use of organic monomer materials become important for the development of molecularly interfaced memory and logic elements. Furthermore, to increase a retention time for the nonvolatile organic memory device as well as to understand an intrinsic memory property, a molecular design of the organic materials is also getting important issue. In this presentation, we report on the OFET memory device built on a silicon wafer and based on films of pentacene and a SiO2 gate insulator that are separated by organic molecules which act as a gate dielectric. We proposed push-pull organic molecules (PPOM) containing triarylamine asan electron donating group (EDG), thiophene as a spacer, and malononitrile as an electron withdrawing group (EWG). The PPOM were designed to control charge transport by differences of the dihedral angles induced by a steric hindrance effect of side chainswithin the molecules. Therefore, we expect that these PPOM with potential energy barrier can save the charges which are transported to the nano-interface between the semiconductor and organic molecules used as the dielectrics. Finally, we also expect that the charges can be contributed to the memory capacity of the memory OFET device.[4]

• 한국가스학회지
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• 제7권4호
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• pp.7-13
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• 2003

본 연구에서는 연소가스의 잠열을 활용함으로서 에너지를 절약하고 배기가스 속의 오염 물질을 저감할 수 있는 콘덴싱 가스보일러의 예혼합버너와 열교환기를 최적화하기 위한 실험을 수행하였다. 본 연구에서 사용된 가스보일러의 열교환기는 상부, 하부 및 코일 열교환기 3개부분으로 구성되어 있다. 상부 열교환기는 예혼합버너를 둘러싸고 있으며 하부 열교환기는 상부열교환기 하단에 설치되어 있다. 그리고, 코일형 열교환기는 상부와 하부열교환기의 바깥 표면을 감싸고 있는 구조로 되어 있다. 본 연구를 통하여 설계된 보일러의 TDR은 당량비 0.75${\~}$0.80 부근에서 약 4:1이며 열효율이 $97\%$로 나타났다. 또한, NOx 및 CO 배출농도는 당량비 0.8 부근에서 각각 20ppm과 140ppm의 낮은 수치를 보였으며 버너의 직경을 기존의 60mm에서 50mm로 변경한 결과, CO의 배출농도가 50ppm까지 현저히 낮아짐을 알 수 있었다.

• 정보교육학회논문지
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• 제23권5호
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• pp.461-467
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• 2019

융복합 응용의 일반화로 라즈베리파이나 아두이노 임베디드형 제어 보드의 활용이 늘고 있다. 이러한 제어장치 설치는 상시 전력이 부재한 상황에서도 운영되어야 하는 경우가 많다. 이러한 경우에 흔히 태양광을 이용하기 때문에 충분한 전력 확보가 쉽지 않다. 본 논문에서는 이러한 저전력 환경 하에서도 작동할 수 있는 효과적인 제어 체계를 제안하고자 한다. 본 논문에서 구성한 실험 기기는 일정한 주기별로 DSLR 카메라 촬영하는 장치이다. 장치의 제어 모듈은 라즈베리파이와 아두이노 보드를 결합한 복합물이며, 아두이노 보드가 정해진 주기별로 라즈베리파이 보드를 동작시키도록 구성하였다. 본 논문에서는 이러한 전력 제어를 위한 프로그램을 개발하였고 이 펌웨어에 의하여 라즈베리파이의 전력 소모를 일자별, 시간별로 측정하여 전체 시스템의 효율성을 검증하였다. 아두이노 보드는 정한 간격마다 라즈베리파이에 전력을 공급하여 카메라에 슈팅 신호를 전송하도록 하였다. 실험결과, 10일간의 실험 기간 동안 일정하고 안정적인 전력 소모가 측정되었다. 결국 아두이노를 결합하여 절전하는 경우 라즈베리의 소비전력량을 약 81% 절감한 것으로 조사되었다.

• 자원리싸이클링
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• 제28권5호
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• pp.30-41
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• 2019

아연의 전세계 생산량은 약 1,300만 톤 정도이며, 철, 알루미늄, 구리에 이어서 네 번째로 많이 사용되는 금속이다. 아연을 리사이클링하여 2차지금을 생산하는 경우 광석으로부터 1차지금을 생산하는데 필요한 에너지의 약 75 %를 절약할 수 있으며, $CO_2$ 발생량은 약 40 %를 절감할 수 있다. 그러나 아연의 주 용도가 철강재의 도금용이기 때문에 아연의 리사이클링율은 약 25 % 수준으로 다른 금속보다 낮은 수준이다. 아연의 리사이클링 원료에는 제강분진, 황동 제조시에 발생하는 분진, 비철금속의 제조공정에서 발생하는 슬러지, 아연 잉곳의 재용해나 용융아연도금을 할때 생성되는 드로스, 폐건전지, 그리고 금속성 스크랩 등이 있다. 제강분진과 폐건전지가 가장 활발하게 리사이클링 되고 있다. 이러한 리사이클링 공정의 대부분은 건식제련법을 응용하고 있으나, 최근에는 건식과 습식의 복합처리에 관해서도 많은 관심이 주어져 있다.

• 설비공학논문집
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• 제21권4호
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• pp.222-228
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• 2009

Various types of refrigerators become popular in the market such as a common refrigerator, kimchi refrigerator and wine cellar. It is required to develop a multi type refrigerator combining these refrigerators to save space and energy consumption. In this study, the performance of a multi type refrigerator, which consists of one machine room and three evaporators, was measured in a bench type multi refrigerator. The multi type refrigerator was tested by varying the number of refrigerator cabinet, refrigerant charge, and temperature conditions. In addition, the multi type refrigerator with a suction line heat exchanger(SLHX) was tested to improve system performance. Based on the experimental data, the multi type refrigerator showed better performance than the conventional refrigerator(single type system). Besides, the COP of the single system increased from 1.0 to 1.37, and those of the dual and triple system increased from 1.29 to 1.39, and 1.22 to 1.51, respectively, by applying the SLHX.

• 융합신호처리학회논문지
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• 제22권3호
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• pp.116-121
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• 2021

에너지를 절약하기 위해 고효율 히트펌프를 개발하기 위한 많은 연구가 이루어지고 있으며, 실외기 코일에 발생하는 서리가 발생하는 현상을 줄이거나 없애기 위한 연구도 동시에 이루어지고 있다. 계절과 관계없이 히트펌프의 실외기에 서리가 발생하지 않는 연구를 진행할 수 있도록 자연 상태와 동일한 조건에서 실험할 수 있는 곡선형 항온챔버를 구축하였다. 이러한 곡선형 항온챔버가 실험 장치로서 타당성을 갖추고 있는지 검증하기 위해 시뮬레이션을 하였다. CFD 조건은 곡선형 항온챔버 내에 위치한 실외기 앞의 직선형 덕트 길이를 덕트 관경의 1배, 5배, 10배, 15배로 하였다. 그 결과 덕트 관경의 10배 길이로 시뮬레이션했을 때 자연 상태와 가장 유사하다는 것을 알게 되었다.

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.374-388
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• 2022

Cloud computing has been one of the most critical technology in the last few decades. It has been invented for several purposes as an example meeting the user requirements and is to satisfy the needs of the user in simple ways. Since cloud computing has been invented, it had followed the traditional approaches in elasticity, which is the key characteristic of cloud computing. Elasticity is that feature in cloud computing which is seeking to meet the needs of the user's with no interruption at run time. There are traditional approaches to do elasticity which have been conducted for several years and have been done with different modelling of mathematical. Even though mathematical modellings have done a forward step in meeting the user's needs, there is still a lack in the optimisation of elasticity. To optimise the elasticity in the cloud, it could be better to benefit of Machine Learning algorithms to predict upcoming workloads and assign them to the scheduling algorithm which would achieve an excellent provision of the cloud services and would improve the Quality of Service (QoS) and save power consumption. Therefore, this paper aims to investigate the use of machine learning techniques in order to predict the workload of Physical Hosts (PH) on the cloud and their energy consumption. The environment of the cloud will be the school of computing cloud testbed (SoC) which will host the experiments. The experiments will take on real applications with different behaviours, by changing workloads over time. The results of the experiments demonstrate that our machine learning techniques used in scheduling algorithm is able to predict the workload of physical hosts (CPU utilisation) and that would contribute to reducing power consumption by scheduling the upcoming virtual machines to the lowest CPU utilisation in the environment of physical hosts. Additionally, there are a number of tools, which are used and explored in this paper, such as the WEKA tool to train the real data to explore Machine learning algorithms and the Zabbix tool to monitor the power consumption before and after scheduling the virtual machines to physical hosts. Moreover, the methodology of the paper is the agile approach that helps us in achieving our solution and managing our paper effectively.

• 농업과학연구
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• 제49권4호
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• pp.771-783
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• 2022

In this study, the feasibility of alternative tractor Roll Over Protective Structure (ROPS) designed to evaluate conditions required for testing was confirmed. In accordance with Organization for Economic Cooperation and Development (OECD) code 4, the required load energy of the tractor ROPS was determined. First, the tractor ROPS test was performed and a repeated test was performed using a simplified ROPS as an alternative tractor ROPS. The test procedure is first rearward, second lateral, and last forward based on ROPS. The load test device consists of a load cell that measures force and a LVDT that measures deformation. Precision was confirmed by calculating the relative standard deviation of the simplified ROPS repeated test. Accuracy was analyzed by calculating the mean relative error between the mean measured values in the simplified ROPS test and the tractor ROPS test. As a result, the relative standard deviation was less than 2.5% for force and 3.3% for maximum deformation overall, showed the highest precision in lateral load. The mean relative error value for force measured at the lateral load of simplified ROPS was 0.5%, showing the highest accuracy. In the front load test, the mean relative error of maximum deformation was 20.5%, showing the lowest accuracy. The mean relative error (MRE) was high in the forward load test was because of structural factors of the ROPS. The simplified ROPS model is expected to save money and time spent preparing tractors.

• 한국염색가공학회지
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• 제35권2호
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• pp.128-136
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• 2023

Recently, the automobile industry is developing as the demand for automo- biles increases due to industrial development and population growth. In addition, many studies are being conducted to reduce heat loss inside the automobiles in order to save energy inside the automobiles due to environmental regulations. In this study, alumina, nanosilicon, and aerogel, which are adiabatic materials, were filled in PET to manufacture yarn, identify physical and mechanical properties, and weave into fabric to confirm adiabatic performance. As the content of the adiabatic material increased, the tensile strength of the fibers filled with alumina and nanosilicon decreased greatly, and the adiabatic property slightly increased. The tensile strength of fibers filled with the aerogel decreased slightly, but the adiabatic properties were greatly increased. Therefore, it is considered to be due to the large volume fraction in the PET yarn due to the low density of the aerogel.