• 조명전기설비학회논문지
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• 제22권12호
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• pp.176-182
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• 2008

본 연구는 실내공기와 상수의 수질개선을 위하여 소형 평판형 오존발생기(plate-type ozonizer : PTO)를 개발하여 그 특성을 규명한 논문이다. 평판전극의 크기, 개수 및 배치에 따라 다양한 형태의 오존발생기가 고안되었다. 각 형태의 오존발생기의 방전면적은 60[$cm^2$]로 동일하며 방전전력은 최대 30[W]이다. 주요 연구 대상은 방전전력-오존생성농도 특성, 방전전력-오존생성수율 특성, 유량-오존생성농도 특성 및 유량-오존생성수율 특성이다. 오존생성특성은 PTOL-P가 가장 우수하게 나타났으며, 나머지 3종류의 오존발생기($PTO_{P-P}$, $PTO_{C-P}$, $PTO_{T-P}$)에서는 유사한 결과를 얻을 수 있었다.

• 한국작물학회지
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• 제38권4호
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• pp.343-349
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• 1993

본 연구는 벼의 시대적 장려품종들 사이의 수량형질이나 생리적 형질에서의 변화를 살펴 육종에 의한 수량증대의 원인을 밝히고, 생리적 형질의 개량을 통한 수도 수량증대 방안을 찾아 보고져 행하여졌다. 1911년부터 1988년도 사이의 8기의 장려품종을 선택하여 재배한 후 수량형질들을 조사하고 생장해석을 통해 생리적 형질들의 값을 측정하여 품종변천에 따른 이들 형질들의 변이를 비교하였다. 최근에 올수록 장려품종들의 간장은 짧아 졌으며 '70년대 이후의 품종들의 등숙률이나 수확지수는 그 이전의 품종보다 높아 졌으나, 주당수수, 수당입수, 그리고 년입중의 변이에서는 시대적 품종변천에 따른 일정한 경향이 없었다. 순동화율, 엽면적비율, 상대엽면적, 그리고 엽중비율에 있어서도 최신 품종에서 아무런 개량을 찾아 볼 수 없었으며 육종을 통한 수도의 수량증대가 있었다면 그것은 주로 도숙병 저항성 품종 육성이나 단간종의 개발에 따른 도복 감소를 통한 등숙율의 향상과 수확지수의 증대에 기인하였음을 알 수 있었다. 수량증대를 위해서는 순동화율의 증대와 수확지수의 증대가 병행하여 이루워 지는 것이 필요하며 광투과율을 높이기 위해서는 도복이 억제되는 한 장간종을 육성하는 것이 중묘할 것으로 나타났다. 순동화율은 엽면적비율과 부의 상관관계가 있어서 이들을 동시에 증대시키는 것은 어려울 것으로 생각되나 순동화율이 상대생장율에 미치는 기여도는 엽면적비율의 그것보다 커, 순동화율이 높은 품종선발이 보다 유리할 것으로 생각된다. 또한 엽중비율의 증대를 통한 엽면적비율의 증가가 상대생장율을 높이는데 보다 효과적일 것으로 생각된다.

• Structural Engineering and Mechanics
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• 제7권5호
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• pp.433-445
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• 1999

Sandwich panels comprising steel facings and a polystyrene foam core are increasingly used as roof and wall claddings in buildings in Australia. When they are subjected to loads causing bending and/or axial compression, the steel plate elements of their profiled facing are susceptible to local buckling. However, when compared to panels with no foam core, they demonstrate significantly improved local buckling behaviour because they are supported by foam. In order to quantify such improvements and to validate the use of available design buckling stress formulae, an investigation using finite element analyses and laboratory experiments was carried out on steel plates that are commonly used in Australia of varying yield stress and thickness supported by a polystyrene foam core. This paper presents the details of this investigation, the buckling results and their comparison with available design buckling formulae.

• 펄프종이기술
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• 제33권1호
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• pp.8-15
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• 2001

Presence of small amount of old newsprints printed with waterbased flexographic inks leads to a significant loss brightness of the deinked pulp by flotation process. Recently there has been an increased interest in employing neutral deinking processes to solve the problems associated with waterbased flexo ink. A comparative experimental study was performed to evaluate the efficiency of neutral deinking and conventional alkaline deinking for ONP furnishes contaminated with flexo ink. It was shown that neutral deinking provides significant improvements in brightness, yield and freeness as compared with alkaline deinking. Flotation efficiency was different depending upon the type of surfactants used in neutral deinking. The result of this study showed that alcohol type surfactant is superior to fatty acid type surfactant in neutral deinking efficiency.

• 전기학회논문지P
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• 제59권1호
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• pp.47-52
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• 2010

The low power of ultra-wideband (UWB) signal makes the acquisition of UWB signal be a more challenging task. In this paper, we propose the method of high order template signal technique that reduces the synchronization time. Experimental results are presented to show the improvements of performance in the mean acquisition time (MAT) and the probability of detection. The performance compared with the serial search, the truly random search and the random permutation search. It is shown that over typical UWB multipath channels, a random permutation search scheme may yield lower MAT than serial search.

• 한국산업융합학회 논문집
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• 제3권1호
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• pp.17-27
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• 2000

A factorization is an extremely important part of multi-level logic synthesis. The number of literals in a factored form is a good estimate of the complexity of a logic function. and can be translated directly into the number of transistors required for implementation. Factored forms are described as either algebraic or Boolean, according to the trade-off between run-time and optimization. A Boolean factored form contains fewer number of literals than an algebraic factored form. In this paper, we present a new method for a Boolean factorization. The key idea is to build an extended co-kernel cube matrix using co-kernel/kernel pairs and kernel/kernel pairs together. The extended co-kernel cube matrix makes it possible to yield a Boolean factored form. We also propose a heuristic method for covering of the extended co-kernel cube matrix. Experimental results on various benchmark circuits show the improvements in literal counts over the algebraic factorization based on Brayton's co-kernel cube matrix.

• 한국항공운항학회:학술대회논문집
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• 한국항공운항학회 2016년도 춘계학술대회
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• pp.162-177
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• 2016

The government conducted an aviation expert training project in 2013. But unfortunately, only pilots and international experts were targeted and aircraft maintenance engineers that are the most important to safety were not trainee to the training courses. More importantly, the more the absolute number of aircrafts increases, the more demand for aircraft maintenance engineers are going up as well. Through the evaluation indicators for the Government-Sponsored Program Fostering Aviation Personnel(aircraft maintenance engineers). it figured out factors associated with the Government-Sponsored Program Fostering Aircraft Maintenance Engineers and it suggested a baseline data necessary to inspect and manage professional training institutions. Thanks to the development of the evaluation indicators, it is highly expected that difference among institutions will be narrowed, elevated level of management of the institutions will help foster and yield satisfactory aircraft maintenance engineers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.54-57
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• 2001

We studied the characteristics of polishing pad, which can apply STI-CMP process for global planarization of multilevel interconnection structure. Also, we investigated the effects of different sets of polishing pad, such as soft and hard pad. As an experimental result, hard pad showed center-fast type, and soft pad showed edge-fast type. Totally, the defect level has shown little difference, however, the counts of scratch was defected less than 2 on JRlll pad. Through the above results, we can select optimum polishing pad, so we can expect the improvements of throughput and devise yield.

• ETRI Journal
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• 제31권3호
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• pp.263-270
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• 2009

This paper investigates linear soft combination schemes for cooperative spectrum sensing in cognitive radio networks. We propose two weight-setting strategies under different basic optimality criteria to improve the overall sensing performance in the network. The corresponding optimal weights are derived, which are determined by the noise power levels and the received primary user signal energies of multiple cooperative secondary users in the network. However, to obtain the instantaneous measurement of these noise power levels and primary user signal energies with high accuracy is extremely challenging. It can even be infeasible in practical implementations under a low signal-to-noise ratio regime. We therefore propose reference data matrices to scavenge the indispensable information of primary user signal energies and noise power levels for setting the proposed combining weights adaptively by keeping records of the most recent spectrum observations. Analyses and simulation results demonstrate that the proposed linear soft combination schemes outperform the conventional maximal ratio combination and equal gain combination schemes and yield significant performance improvements in spectrum sensing.

• 전기전자학회논문지
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• 제11권4호
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• pp.340-347
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• 2007

This paper proposes a new class of Space-Time Block Codes, which is manipulated from the existing transmit diversity schemes. We analyze the performance and the receiver complexity of the proposed scheme and confirm that the new diversity scheme can yield performance gain over other existing four-transmit antenna cases. By relaxing the diversity criterion on code designs, the proposed space-time code provides a full transmission rate for four-transmit antennas and makes it possible to approach the open-loop Shannon channel capacity. Outage capacity and simulation results are used to show that substantial improvements in performance while maintaining a simple linear processing receiver structure are obtained in frequency selective channels.