• The Korean Journal of Mycology
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• v.26 no.2 s.85
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• pp.239-245
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• 1998

The feasibility of enzymatic hydrolysis of cellulosic materials is dependent on the cost of cellulase, which is strongly influenced by the selection of proper carbon source in the cellulase production medium. When solka floc was used as a carbon source for the production of cellulase by Trichoderma reesei Rut C-30, a maximum of 53.2 U/ml of CMCase activity (4.8 U/ml of FPase activity) was obtained with a concentration of 1 % of solka floc. The cellulase activity decreased to 50% in the presence of 0.5% of glucose in the medium. The production of cellulase was considerably enhanced when solka floc and wheat bran were used together as a carbon source. A medium which contained 1 % of solka floc and 3 % of wheat bran yielded highest cellulase activity: CMCase activity of 76 U/ml and FPase activity of 12.5 U/ml.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.229-233
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• 2007

A long-term rice paddy field, which is located in the National Institute of Crop Science (Suwon city, Korea) has been managed for studying of fertilization and composting impact on paddy soil fertility since 1954. The objective of this research was to evaluate soil quality through dehydrogenase analysis in long-term paddy soil treatment plots, such as control, N fertilization (N), NPK fertilization (NPK), and rice straw compost with NPK (CNPK). Dehydrogenase-producing bacterial population developing red-colored triphenyl formazan (TPF) was highly correlated to the dehydrogenase activity in rice paddy soils sampled prior to waterlog. The dehydrogenase-producing bacterial population and dehydrogenase activity was comparatively high in plots of NPK, and CNPK, which organic matter content was relatively high.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.4
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• pp.13-19
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• 2010

MOSFET with deuterium-incorporated gate oxide shows enhanced reliability compared to conventional MOSFET. We present an alternative process whereby deuterium is delivered to the location where the gate oxide reside by an implantation process. Deuterium ions were implanted using two different energies to account for the topography of the overlaying layers and placing the D peak at the top of gate oxide. A short anneal at forming gas was performed to remove the D-implantation damage. We have observed that deuterium ion implantation into the gate oxide region can successfully remove the interface states and the bulk defects. But the energy and the dose of the deuterium implant need to be optimized to maintain the Si substrates dopant activation, while generating deuterium bonds inside gate oxide. CV and IV characteristics studies also determined that the deuterium implant dose not degrade the transistor performance.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.3
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• pp.74-79
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• 2008

In an H.264/AVC video encoder, the motion estimation at fractional pixel accuracy improves a coding efficiency and image quality. However, it requires additional computation overheads for fractional search and interpolation, and thus, reducing the computation complexity of fractional search becomes more important. This paper proposes fast fractional search algorithms by combining the SASR(Simplified Adaptive Search Range) and the MSDSP(Mixed Small Diamond Search Pattern) with the predicted fractional motion vector. Compared with the full search and the prediction-based directional fractional pixel search, the proposed algorithms can reduce up to 93.2% and 81% of fractional search points, respectively with the maximum PSNR lost less than 0.04dB. Therefore, the proposed fast search algorithms are quite suitable for mobile applications requiring low power and complexity.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.224-224
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• 2016

수문 순환과 물 수지에 관한 연구는 강수량, 지표유출량, 지하수, 토양수분 및 증발산량 등에 대한 관측이 이루어질 때 실제로 규명될 수 있다. 하지만, 수문 순환과 물수지 평가에 중요한 부분을 차지하는 증발산량의 경우 관측값보다 단순한 가정이나 경험식에 의한 추정값을 사용하고 있어 그 자료의 신뢰성에 대해서도 꾸준히 문제가 제기되어 왔다. 따라서, 수문 순환과 물수지의 정량적인 분석을 위해서는 수문 순환 과정에서 상당부분을 차지하는 증발산량의 측정(실측)과 자료의 축척이 필요한 실정이다. 본 연구는 국토교통부의 기초수문자료 구축사업의 일환으로 수행되고 있으며, 수문자료의 다양화 목적을 가지고 에디공분산 기술을 사용하여 증발산량을 직접 관측하고 있다. 관측지점은 한반도의 약 70%를 차지하는 산림지 중 대표적 식생 기능 형태인 혼효림으로 구성된 지점(설마천 관측소, 2007년 8월부터)과, 인위적인 관개가 이루어지는 논경지(청미천 관측소, 2008년 8월부터)에서의 증발산량 측정을 수행하였다. 그 결과 두 지점에서 증발산량의 계절 및 경년 변동 특성을 파악 할 수 있었다. 혼효림(설마천 관측소)에서 산정된 증발산량은 2008년 471.7mm, 2009년 408.4mm, 2010년 489.4mm, 2011년 387.0mm, 2012년 323.3mm, 2013년 293.3mm, 2014년 360.9mm, 2015년 419.6mm이고, 강수량 대비 증발산량은 18.9%~56.2%를 보였다. 논경지(청미천 관측소)에서 산정된 증발산량은 2009년 571.8mm, 2010년 650.6mm, 2011년 523.9mm, 2012년 509.8mm, 2013년 467.9mm 2014년 533.9mm, 2015년 600.5mm이고, 강수량 대비 증발산량은 25.6%~71.4%를 보였다. 강수량 대비 비율의 최대값은 설마천 관측소는 2014년, 청미천 관측소는 2015년에 발생하였다.. 평균 증발산량 비율은 산림지인 설마천 관측소보다 논경지인 청미천 관측소가 평균 15.5%정도 높게 나타났다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.465-469
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• 2018

여울과 소는 하천의 물리적 특성(경사, 하상재료, 지질의 형태)에 따라 자연적으로 형성되며, 이에 따라 하도 지형이 다양하게 변화하고 생물의 서식처의 다양성이 확보됨으로써 하천의 생태환경에 긍정적인 영향을 미친다. 우리나라의 경우 하천주변의 충적평야에서 벼농사가 이루어지므로 아주 많은 농업용 취수보가 설치되어 있으며, 또한 하상경사가 급하므로 하상안정을 위하여 낙차공 등의 하상유지공도 상류에 많이 설치되어 있는 실정이다. 취수보 및 하상유지공 등의 하천횡단구조물은 하상의 종적 연속성을 단절시키고, 상류측에 대규모의 정체수역을 형성함으로써 하도의 자연적인 여울-소 지형특성을 훼손함과 더불어 흐름 다양성을 단순화시킨다. 이러한 하천횡단구조물의 부정적 영향은 수서동물의 이동통로를 차단할 뿐 아니라 수서동물의 서식처를 단순화함으로써 생태계에 부정적 영향을 미쳐서 생물종의 다양성을 훼손하는 심각한 문제를 초래하고 있다. 본 연구에서는 하천횡단구조물이 여울-소의 형성에 미치는 영향을 규명하기 위하여 경상남도의 하천 중 유역면적이 $100km^2$ 이상인 하천 중에서 하천횡단구조물의 영향을 받는 하천의 구간과 하천횡단구조물의 영향을 받지 않는 하천의 구간을 분류하여 하천횡단구조물이 여울-소에 미치는 영향을 분석하였다. 하천횡단구조물이 여울-소 형성에 미치는 영향을 하상경사에 따라 구분하였으며 그에 따라 하천횡단구조물이 여울에 미치는 영향을 비교하였다. 상류에는 배수위의 영향으로 정체수나 인위적인 평여울이 발생하며, 하류에는 낙차로 인하여 소나 여울이 발생하지만, 그 빈도는 하천횡단구조물의 설치 간격에 따라 자연상태에서 보다는 현저히 낮게 나타났다. 경남 지방에서 유역면적 $100km^2$ 이상인 30개 하천 중에서 16개의 하천에 설치된 하천차단시설물은 보 405개소와 낙차공 129개 총 534개를 조사하였으며, 하천차단시설물의 설치간격 및 높이가 여울-소의 형성에 가장 큰 영향을 미친다는 사실을 확인하였다.

• Journal of Digital Forensics
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• v.12 no.3
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• pp.27-38
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• 2018

Recently, as the amount of digital data rapidly increases, a large storage space is required. RAID is a system that can manage large capacity storage space. Storage space provided by Windows is a type of software RAID. Storage space has been supported since Windows 8, Windows Server 2012, and no analysis has been done on the functionality. To analyze system using storage space, analysis of storage space function and reconstruction method of virtual disk should be studied. In this paper, we briefly describe the layout of existing RAID, explain the layout and metadata of storage space of software RAID, present reconstruction method of virtual disk by disk layout, and verify the result through experiments.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1309-1316
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• 2018

Cattle estrus detection system based on Internet of Things is designed and implemented by using Arduino pro-mini, gyroscope, acceleration sensor, bluetooth master and slave module. The implemented system measures cattle's moving and the measured data are transmitted to the computer connected to RX module by bluetooth TX module. They are plotted in 2-dimensional graph on the computer monitor and the number of transition at each sensor axis are calculated from the graph. The detected and gathered data from the system are analyzed by the proposed algorithm to decide which cows are in the estrus or not. The method to apply bluetooth scatternet is shown and the proposed system can be used to increase the success rate of artificial insemination in normal estrus by detecting the cow's behaviors such as the number of jumping. In this paper, the implemented cattle behavior detecting the system(TX module) are strapped on cattle's leg and it measures the cattle behaviors for determining where that a cattle is estrus or not by the proposed algorithm.

• The Korean Journal of Applied Statistics
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• v.33 no.6
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• pp.739-751
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• 2020

Seoul public bike program facilitates access to bicycles and offers potential for greater mobility and health for users. Furthermore, it would have positive impacts on transport congestion, energy use, and the environment. Hence, it is important to find future rental locations by taking to account both bike-demand and regional imbalance. This paper first finds eligible candidates of rental locations with the required spatial conditions such as a sufficient sidewalk width and accessibility of bike pick-up vehicles. And then, estimates public bike daily usage for each selected location via random forest based on Seoul public bike historical usage, Seoul geographical features, regional characteristics, and populations. This study contributes to a better comprehension of the Seoul public bike program, and would be useful in determining new public bike rental locations.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.583-590
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• 2022

With the release of the Bitcoin source in 2009, cryptocurrencies are continuously developing and expanding the market. Recently, new applicability is expanding centered on NFT coin and metaverse payment service. In particular, the Central Cryptocurrency Exchange actively supports relay transactions between cryptocurrencies or between traditional fiat currencies and cryptocurrencies. The cryptocurrency trading market based on such a central exchange encouraged speculative factors of cryptocurrencies, strongly arousing speculation and futility of cryptocurrencies. In addition, the central cryptocurrency exchange induces the centralization of users and virtual assets, thereby hindering the decentralization and security enhancement strategies of the block chain. Therefore, this study describes the current status and problems of centrally controlled centralized cryptocurrency exchanges in service, and presents a distributed cryptocurrency exchange modeling strategy and major issues as a decentralization model of the exchange. This research can strengthen the anonymity, decentralization, and autonomy of cryptocurrency based on blockchain.