• 디지털산업정보학회논문지
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• 제12권1호
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• pp.51-61
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• 2016

Because the Apple Pay which created by U.S's Apple Inc. and launch of Samsung pay in last August in domestic, people have high interest in Pin-Tech industries and new method of easy payment. In this paper, it will study newly introduced Pin-Tech industries and marketability of Pin-Tech industries. Also it will propose safe use of Pin-Tech services based on cases in domestic and overseas. This paper is organized as follows. In Chapter 2, it will study concept of Pin-Tech services and status of Pin-Tech services in domestic and overseas. In Chapter 3, it will look technical trends of Pin-Tech services. In Chapter 4, it will propose direction based on analysis of cases of Pin-Tech services. This paper will finish with conclusion in Chapter 5. Given the global trends, Korea is now just took the first steps in new Pin-Tech era. The Pin-Tech services are in situations that it is not yet activated in domestic due to the various financial regulations and procedures. In this paper, it will shows cases of concerns of Pin-Tech services and domestic authentication which relates to easy payment certification. If Pin-Tech services are develop with easy payment certification and adapt to domestic environment and develop based on stability and security as mentioned in this paper, domestic Pin-Tech services and security technology will grow to the world level. Also it requires unceasing research and efforts from relevant government officials, security companies and Pin-Tech ICT companies.

• KSBB Journal
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• 제20권3호
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• pp.183-191
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• 2005

현재 석유화학 및 화학분야에서 이온성 액체를 이용한 많은 연구가 이뤄지고 있다. 휘발성 유기용매의 대체 물질로서 각광을 받고 있는 이온성 액체는 최대 250억불 이상의 시장을 형성할 것으로 기대된다 위에서 말한 바와 같이 생물공학 분야에서도 이온성 액체를 이용한 연구가 시작되어 용매로 사용하는 방법, 분리매개체로서 사용하는 방법 등 다양하게 이용되고 있다. 이러한 이온성 액체는 효소의 활성, 안정성을 증대시킬 뿐 아니라, 분리 과정도 손쉽게 실현할 수 있다. 또한 환경적 측면과, 경제적인 측면을 고려하여 청정용매로 널리 사용 할 수 있을 것이다. 앞에서 말한 바와 같이 생물공학에서 이온성 액체의 응용 가능성은 무한하다 볼 수 있다. 또한, 나노공학과 생물공학을 접목하는 분야에서도 널리 이온성 액체가 쓰일 수 있을 것이다. 유럽과 미국에서는 주로 청정용매로서의 응용에 대한 연구를, 일본에서는 주로 이온 전도성 재료로서의 응용에 대한 연구를 활발히 하고 있다. 이러한 전 세계적인 연구의 활성화에 비하여 국내 상황은 대학 및 연구소에서 산발적으로 연구가 진행되고 있는 수준이다. 이에 국내에서도 이에 대한 관심과 더불어 정부 및 기업체, 대학 및 연구소에 의한 컨소시엄을 형성하여 보다 체계적인 연구지원이 이뤄져야 할 것이다.

• The Journal of Advanced Prosthodontics
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• 제6권6호
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• pp.456-461
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• 2014

PURPOSE. Translucency and colour stability are two most important aspects for an aesthetic dental restoration. Glass ceramic restorations are popular amongst clinicians because of their superior aesthetic properties. In the last decade, zirconia has generated tremendous interest due to its favorable mechanical and biological properties. However, zirconia lacks the translucency that lithium disilicate materials possess and therefore has limitations in its use, especially in esthetically demanding situations. There has been a great thrust in research towards developing translucent zirconia materials for dental restorations. The objective of the study was to evaluate and compare the transmittance of a translucent variant of zirconia to lithium disilicate. MATERIALS AND METHODS. Two commercially available zirconia materials (conventional and high translucency) and 2 lithium disilicate materials (conventional and high translucency) with standardized dimensions were fabricated. Transmittance values were measured for all samples followed by a microstructural analysis using a finite element scanning electron microscope. One way analysis of variance combined with a Tukey-post hoc test was used to analyze the data obtained (P=.05). RESULTS. High translucency lithium disilicate showed highest transmittance of all materials studied, followed by conventional lithium disilicate, high translucency zirconia and conventional zirconia. The difference between all groups of materials was statistically significant. The transmittance of the different materials correlated to their microstructure analysis. CONCLUSION. Despite manufacturers' efforts to make zirconia significantly more translucent, the transmittance values of these materials still do not match conventional lithium disilicate. More research is required on zirconia towards making the material more translucent for its potential use as esthetic monolithic restoration.

• 대한원격탐사학회지
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• 제36권4호
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• pp.573-586
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• 2020

PM (particulate matter) is of interest to everyone because it can have adverse effects on human health by the infiltration from respiratory to internal organs. To date, many studies have made efforts for the prediction of PM10 and PM2.5 concentrations. Unlike previous studies, we conducted the prediction of tomorrow's PM10 concentration for the Air Korea stations using Chinese PM10 data in addition to the satellite AOD and weather variables. We constructed 230,639 matchups from the raw data over 3 million and built an RF (random forest) model from the matchups to cope with the complexity and nonlinearity. The validation statistics from the blind test showed excellent accuracy with the RMSE (root mean square error) of 9.905 ㎍/㎥ and the CC (correlation coefficient) of 0.918. Moreover, our prediction model showed a stable performance without the dependency on seasons or the degree of PM10 concentration. However, part of coastal areas had a relatively low accuracy, which implies that a dedicated model for coastal areas will be necessary. Additional input variables such as wind direction, precipitation, and air stability should also be incorporated into the prediction model as future work.

• Steel and Composite Structures
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• 제19권5호
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• pp.1115-1144
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• 2015

Current climate conditions along with advances in technology make further design and verification methods for structural strength and reliability of wind turbine towers imperative. Along with the growing interest for "green" energy, the wind energy sector has been developed tremendously the past decades. To this end, the improvement of wind turbine towers in terms of structural detailing and performance result in more efficient, durable and robust structures that facilitate their wider application, thus leading to energy harvesting increase. The wind tower industry is set to expand to greater heights than before and tapered steel towers with a circular cross-section are widely used as more capable of carrying heavier loads. The present study focuses on the improvement of the structural response of steel wind turbine towers, by means of internal stiffening. A thorough investigation of the contribution of stiffening rings to the overall structural behavior of the tower is being carried out. These stiffening rings are placed along the tower height to reduce local buckling phenomena, thus increasing the buckling strength of steel wind energy towers and leading the structure to a behavior closer to the one provided by the beam theory. Additionally to ring stiffeners, vertical stiffening schemes are studied to eliminate the presence of short wavelength buckles due to bending. For the purposes of this research, finite element analysis is applied in order to describe and predict in an accurate way the structural response of a model tower stiffened by internal stiffeners. Moreover, a parametric study is being performed in order to investigate the effect of the stiffeners' number to the functionality of the aforementioned stiffening systems and the improved structural behavior of the overall wind converter.

• 폴리머
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• 제35권2호
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• pp.124-129
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• 2011

최근 목분/플라스틱 복합체(WPC)가 많은 관심을 끌고 있다. 본 연구에서는 커플링제 및 나노점토가 함유된 목분/폴리에틸렌(PE) 복합체 패널을 용융혼합 후 압축 성형하여 제조하였다. 5 종의 말레산무수물 그래프트 폴리에틸렌(MAPE) 커플링제에 대해 시험하여 가장 우수한 커플링제 및 힘량을 결정하였다. WPC의 기계적 특성은 UTM으로, 열적 특성은 TGA, DMA, DSC, TMA로 측정하였다. 유기점토를 소량(1 phr) 만 첨가하여도 WPC의 인장강도 및 굴곡강도 결정화도가 증가하는 경향을 보였으며 저장탄성률과 치수안정성은 크게 증가하였다. SEM으로 분석한 결과 커플링제에 의한 목분/PE 계면결합력 향상 효과가 매우 큼을 알 수 있었다. 최적의 커플링제를 선정하여 힘량을 최적화하고 소량의 유기점토를 첨가함으로써 우수한 성능의 목분/PE 복합체를 제조할 수 있었다.

• 산업융합연구
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• 제18권1호
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• pp.79-85
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• 2020

최근 원격조종과 자율조종이 가능한 무인항공기(RPAS:Remotely Piloted Aircraft System)가 택배 드론, 소방드론, 구급 드론, 농업용 드론, 예술 드론, 드론 택시 등 각 산업 분야와 공공기관에서의 관심과 활용이 높아지고 있다. 자율조종이 가능한 무인드론의 안정성 문제는 앞으로 드론 산업의 발달과 함께 진화하면서 해결해야 할 가장 큰 과제이기도 하다. 드론은 자율비행제어 시스템이 지정한 경로로 비행하고 목적지에 정확하게 자동 착륙을 수행할 수 있어야 한다. 본 연구는 드론의 센서와 GPS의 위치 정보의 오류를 보완하는 방법으로서 착륙지점 영상을 통해 드론의 도착 여부를 확인하고 정확한 위치에서의 착륙을 제어하는 기법을 제안한다. 서버에서 도착지 영상을 구글맵 API로부터 수신받아 딥러닝으로 학습하고, 드론에 NAVIO2와 라즈베리파이, 카메라를 장착하여 착륙지점의 이미지를 촬영한 다음 이미지를 서버에 전송한다. Deep Learning으로 학습된 결과와 비교하여 임계치에 맞게 드론의 위치를 조정한 후 착륙지점에 자동으로 착륙할 수 있다.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.51-58
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• 2011

The energy makes the basic element which improves the quality of life with motive power of industry and life. However, using the fossil fuel resources was restricted through it's abuse and exhaustion, and that cause a global warming resultingly. According to the reason, the world increased the interest that are stability and use of new and renewable energy which is clean energy with environment. Therefore, the property data of new and renewable is needed for developing and supplying the energy. In other words, the data of new and renewable energy becomes the standards for supply and evaluation of new and renewable energy with development of industry and technology. Also, the necessity came to the fore as the reference and standards of new and renewable energy data. Therefore, in this study, we evaluate and collect the solar radiation data as the new and renewable data and process the collected data through the standards for valuation. We evaluate uncertainty with standards which are NREL, WMO, and GUM. Whereby the data becomes reference standards data and gains the credibility. For the reliability data, we correct the measuring instrument with correction period. Using the DQMS and SERI QC, we efficiently manage and evaluate the solar radiation data. As a result, we evaluate uncertainty as 1,120 case about 16 area. we achieve credibility of data from evaluated solar radiation data and provide an accurate information to user. The annual average of horizontal radiation presents between 1,484 and 4,577, then the uncertainty evaluates from 163 to 453. The error of uncertainty presents smaller than the measurement values. So, we judge a credibility of data by expression of reliability quantitatively. In additional, the reference standards data which is possible to approach anywhere will be used for the supporting related industry and policy making.

• 한국농공학회논문집
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• 제57권1호
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• pp.99-109
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• 2015

In the construction industry, the interest for recycling aggregates is rising as more people demand for alternatives due to lack of supply of natural aggregates and environmental problems. However, in order for recycled aggregates to be used in infrastructures, stability and other factors need to be verified. Therefore, the objective of this study is to analyze the sensitivity of soil properties to secure slope safety according to various heights of embankment when bottom ash and dredged soil mixture is applied in the embankment. In most cases, all heights were safe for the slide for the embankment whether the water level is full or sudden draw down. The result of the sensitivity analysis revealed that the unit weight of embankments is highest among all factors to be considered. However, the sensitivity of the unit weight became smaller and the sensitivity of the friction angle of embankments increased with the height of embankments. The sensitivity of factors of core materials is very small because the core has weaker physical properties than those of the embankment. The effect of the height for each factor is different for each slope and water levels. The sensitivity of the unit weight of embankments is most affected when the height is 60m in the upstream slope. To conclude, bottom ash and dredged soil mixture can be applied in the embankment and different factors must be considered in different scale because the sensitivity depends highly on the height of embankments.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1653-1663
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• 2010

The first gene (${\alpha}$-gal1) encoding an extracellular ${\alpha}$-Dgalactosidase from the thermophilic fungus Talaromyces emersonii was cloned and characterized. The ${\alpha}$-gal1 gene consisted of an open reading frame of 1,792 base pairs interrupted by six introns that encoded a mature protein of 452 amino acids, including a 24 amino acid secretory signal sequence. The translated protein had highest identity with other fungal ${\alpha}$-galactosidases belonging to glycosyl hydrolase family 27. The ${\alpha}$-gal1 gene was overexpressed as a secretory protein with an N-terminal histidine tag in the methylotrophic yeast Pichia pastoris. Recombinant ${\alpha}$-Gal1 was secreted into the culture medium as a monomeric glycoprotein with a maximal yield of 10.75 mg/l and purified to homogeneity using Hisbinding nickel-agarose affinity chromatography. The purified enzyme was maximally active at $70^{\circ}C$, pH 4.5, and lost no activity over 10 days at $50^{\circ}C$. ${\alpha}$-Gal1 followed Michaelis-Menten kinetics ($V_{max}\;of\;240.3{\mu}M/min/mg,\;K_m\;of\;0.294 mM$) and was inhibited competitively by galactose ($K_m{^{obs}}$ of 0.57 mM, $K_i$ of 2.77 mM). The recombinant T. emersonii ${\alpha}$-galactosidase displayed broad substrate preference, being active on both oligo- and polymeric substrates, yet had strict specificity for the ${\alpha}$-galactosidic linkage. Owing to its substrate preference and noteworthy stability, ${\alpha}$-Gal1 is of particular interest for possible biotechnological applications involving the processing of plant materials.