• Nuclear Engineering and Technology
• /
• 제27권3호
• /
• pp.336-343
• /
• 1995

적응제어의 한 방식인 자기동조제어(STR) 방식이 비선형 노심 모델의 출력 조정에 적용된다. 적응제어는 비선형, 시변 및 확률(Stochastic) 시스템을 위한 준최적 제어기를 설계하기 위한 적절한 제어 방식이다. 제어계통은 미지의 시변 파라메타를 갖는 3차 선형 모델에 기초한다. 파라메타는 가변 망각계수를 도입한 늑장 최소자승법에 의하여 매시간(Time Step) 순환적으로 평가된다. 평가된 파라메타를 이용하여 한 스텝 먼저 냉자재 평균온도가 예측되고 이 예측된 값과 Setpoint 값과의 차이를 최소화함은 물론, 제어봉의 움직임을 막고자 가중(Weighted) One-step-ahead 제어기가 설계된다. 또한 적분동작이 첨가되어 정상상태 에러가 제거된다. 넓은 운전영역을 포괄하는 비선형 PWR 모델이 원자로 출력 조정을 위한 본 제어기를 시뮬레이션하는데 이용되었다. 시뮬레이션 결과로부터 본 제어기의 성능이 우수한 것으로 판명되었다.

• 천문학회지
• /
• 제45권6호
• /
• pp.167-173
• /
• 2012

Inter-granular Bright Points (igBPs) are small-scale objects in the Solar photosphere which can be seen within dark inter-granular lanes. We present a new algorithm to automatically detect and extract igBPs. Laplacian and Morphological Dilation (LMD) technique is employed by the algorithm. It involves three basic processing steps: (1) obtaining candidate "seed" regions by Laplacian; (2) determining the boundary and size of igBPs by morphological dilation; (3) discarding brighter granules by a probability criterion. For validating our algorithm, we used the observed samples of the Dutch Open Telescope (DOT), collected on April 12, 2007. They contain 180 high-resolution images, and each has a $85{\times}68\;arcsec^2$ field of view (FOV). Two important results are obtained: first, the identified rate of igBPs reaches 95% and is higher than previous results; second, the diameter distribution is $220{\pm}25km$, which is fully consistent with previously published data. We conclude that the presented algorithm can detect and extract igBPs automatically and effectively.

• 펄프종이기술
• /
• 제32권5호
• /
• pp.72-79
• /
• 2000

On the other hand, the fiber orientation at the surface and middle layer of the sheet controls the bending stiffness of paperboard. Therefore, a reliable measurement of paper surface fiber orientation gives us a magnificent tool to investigate and predict paper curling and cockling tendency, and provides the necessary information to fine-tune the manufacturing process for optimum quality. Many papers, especially heavily calendered and coated grades, do resist liquid and gas penetration very much, being beyond the measurement range of the traditional instruments or resulting inconveniently long measuring time per sample. The increased surface hardness and use of filler minerals and mechanical pulp make a reliable, non-leaking sample contact to the measurement head a challenge of its own. Paper surface coating causes, as expected, a layer which has completely different permeability characteristics compared to the other layers of the sheet. The latest developments in sensor technologies have made it possible to reliably measure gas flow n well controlled conditions, allowing us to investigate the gas penetration of open structures, such as cigarette paper, tissue or sack paper, and in the low permeability range analyze even fully greaseproof papers, silicon papers, heavily coated papers and boards or even detect defects in barrier coatings! Even nitrogen or helium may be used as the gas, giving us completely new possibilities to rank the products or to find correlation to critical process or converting parameters. All the modern paper machines include many on-line measuring instruments which are used to give the necessary information for automatic process control systems. Hence, the reliability of this information obtained from different sensors is vital for good optimizing and process stability. If any of these on-line sensors do not operate perfectly as planned (having even small measurement error or malfunction), the process control will set the machine to operate away from the optimum, resulting loss of profit or eventual problems in quality or runnability. To assure optimum operation of the paper machines, a novel quality assurance policy for the on-line measurements has been developed, including control procedures utilizing traceable, accredited standards for the best reliability and performance.

• International Journal of Advanced Culture Technology
• /
• 제9권2호
• /
• pp.100-105
• /
• 2021

Contactless service is rapidly emerging as a new growth strategy due to consumers who are reluctant to the face-to-face situation in the global pandemic of coronavirus disease 2019 (COVID-19), and various technologies are being developed to support the fast-growing contactless service market. In particular, the restaurant industry is one of the most desperate industrial fields requiring technologies for contactless service, and the representative technical case should be a kiosk, which has the advantage of reducing labor costs for the restaurant owners and provides psychological relaxation and satisfaction to the customer. In this paper, we propose a solution to the restaurant's store operation through the unmanned kiosk using a state-of-the-art artificial intelligence (AI) technology of image recognition. Especially, for the products that do not have barcodes in bakeries, fresh foods (fruits, vegetables, etc.), and autonomous restaurants on highways, which cause increased labor costs and many hassles, our proposed system should be very useful. The proposed system recognizes products without barcodes on the ground of image-based AI algorithm technology and makes automatic payments. To test the proposed system feasibility, we established an AI vision system using a commercial camera and conducted an image recognition test by training object detection AI models using donut images. The proposed system has a self-learning system with mismatched information in operation. The self-learning AI technology allows us to upgrade the recognition performance continuously. We proposed a fully automated payment system with AI vision technology and showed system feasibility by the performance test. The system realizes contactless service for self-checkout in the restaurant business area and improves the cost-saving in managing human resources.

• International Journal of Computer Science & Network Security
• /
• 제21권4호
• /
• pp.255-263
• /
• 2021

Smart grid is a fully-automated, bi-directional, power transmission network based on the physical grid system, which combines sensor measurement, computer, information communication, and automatic control technology. Blockchain technology, with its security features, can be integrated with Smart Grids to provide secure and efficient power management and transmission. This paper dicusses the deployment of Blockchain technology in Smart Grid. It presents application areas and protocols in which blockchain can be applied to in securing smart grid. One application of each area is explored in detail, such as efficient peer-to-peer transaction, lower platform costs, faster processes, greater flexibility in power generation to transmission, distribution and power consumption in different energy storage systems, current barriers obstructing the implementation of blockchain applications with some level of maturity in financial services but concepts only in energy and other sectors. Wide range of energy applications suggesting a suitable blockchain architecture in smart grid operations, a sample block structure and the potential blockchain technicalities employed in it. Also, added with efficient data aggregation schemes based on the blockchain technology to overcome the challenges related to privacy and security in the smart grid. Later on, consensus algorithms and protocols are discussed. Monitoring of the usage and statistics of energy distribution systems that can also be used to remotely control energy flow to a particular area. Further, the discussion on the blockchain-based frameworks that helps in the diagnosis and maintenance of smart grid equipment. We have also discussed several commercial implementations of blockchain in the smart grid. Finally, various challenges have been discussed for integrating these technologies. Overall, it can be said at the present point in time that blockchain technology certainly shows a lot of potentials from a customer perspective too and should be further developed by market participants. The approaches seen thus far may have a disruptive effect in the future and might require additional regulatory intervention in an already tightly regulated energy market. If blockchains are to deliver benefits for consumers (whether as consumers or prosumers of energy), a strong focus on consumer issues will be needed.

• International Journal of Computer Science & Network Security
• /
• 제21권6호
• /
• pp.258-268
• /
• 2021

Online learning systems are becoming an effective educational medium for many universities. The accessibility of online learning system in universities means that every student, including the visually impaired, is able use all the site's services. This research focuses on investigating the accessibility of online learning systems for visually impaired users. The paper purpose is to understand the perception of visually impaired undergraduate students towards Blackboard's accessibility and to make recommendations for a new Blackboard design with accessible features that support their needs. Impact of a new Blackboard design with accessible features on visually impaired students, using Taif University students as a case study is evaluated in this paper, as it is similar to most learning systems used by Saudi universities. A study on Taif University's utilization of Blackboard was conducted using mixed method approaches (an automatic tool and a user study). In the first phase, Taif's use of Blackboard was evaluated by the web accessibility tool called AChecker. In the second phase, we conducted a user study to verify previously discovered accessibility challenges to fully assess them according to the accessibility and usability guidelines. In this study, the accessibility of Taif University's Blackboard was evaluated by thirteen visually impaired undergraduate students. The results of the study show that Blackboard has accessibility issues, which are confusing navigation, incompatibility with assistive technologies, untitled pages or parts, unclear identification for visual elements, and inaccessible PDF files. This paper also introduces a set of recommendations that aim to improve the accessibility of Blackboard and other educational websites developed for this population. It also highlights the serious need for universities to enhance web accessibility for online learning systems for students with disabilities.

• 한국지반공학회논문집
• /
• 제38권11호
• /
• pp.87-95
• /
• 2022

국토지반정보 포털시스템이 구축된 지반정보는 최근 설계, 시공, 지하안전관리, 재해재난 평가 등 다양한 분야에서 활용되고 있다. 그러나 전국적으로 기 구축된 약 30여만공의 지반정보는 누락되거나 잘못된 정보를 다수 포함하고 있어 데이터 활용시 신뢰도를 확보하기가 어렵다. 따라서 분석 데이터의 신뢰도를 확보하기 위해서는 지반정보를 활용하기 전 단계에서 지반정보의 정제(품질관리)가 반드시 필요하다. 본 연구에서는 딥러닝 기법 중 하나인 인공신경망 기법을 활용하여 지반정보를 자동으로 품질관리 하는 방안에 대하여 제안하였다. 특히, 가장 일반적으로 사용되는 정보인 표준관입시험 결과와 지층정보를 이용하여 지반정보의 이상치를 탐지하였다. 서울시 지반정보 데이터를 이용하여 분석하였으며, 검증데이터에 대한 오분류 비율은 5.4%로 확인되었다. 신경망 모델에서 이상치 분류된 데이터만을 추후에 검사함으로써 효율적으로 이상치를 탐지할 수 있을 것으로 기대된다.

• Geomechanics and Engineering
• /
• 제28권5호
• /
• pp.531-546
• /
• 2022

Ground displacements caused by the construction of overlapping twin shield tunnels with small turning radius are complex, especially under special geological conditions of construction. To investigate the ground displacements caused due to shield machines in the unique calcareous sand layers in Israel for the first time and determine the main factors affecting the ground displacements, field monitoring, laboratory geological analysis, theoretical calculations, and parameter studies were adopted. By using rod extensometers, inclinometers, total stations, and automatic segment-displacement monitors, subsurface tunneling-induced displacement, surface settlement, and displacement of the down-track tunnel segments caused by the construction of an up-track tunnel were analyzed. The up-track tunnel and the down-track tunnel pass through different stratum, resulting in different construction parameters and ground displacements. The laws of variation of thrust and torque, soil pressure in the chamber, excavated soil quantity, synchronous grouting pressure, and grout volume of the two tunnels from parallel to fully overlapping orientations were compared. The thrust and torque of the shield in the fine sand are larger than those in the Kurkar layer, and the grouting amount in fine sand is unstable. According to fuzzy statistics and Gaussian curve fitting of the shield tunneling speed, the tunneling speed in the Kurkar stratum is twice that in the fine-sand stratum.

• Journal of Animal Science and Technology
• /
• 제64권3호
• /
• pp.531-538
• /
• 2022

In Italy, buffalo mozzarella is a largely sold and consumed dairy product. The fraudulent adulteration of buffalo milk with cheaper and more available milk of other species is very frequent. In the present study, Fourier transform infrared spectroscopy (FTIR), in combination with multivariate analysis by partial least square (PLS) regression, was applied to quantitatively detect the adulteration of buffalo milk with cow milk by using a fully automatic equipment dedicated to the routine analysis of the milk composition. To enhance the heterogeneity, cow and buffalo bulk milk was collected for a period of over three years from different dairy farms. A total of 119 samples were used for the analysis to generate 17 different concentrations of buffalo-cow milk mixtures. This procedure was used to enhance variability and to properly randomize the trials. The obtained calibration model showed an R² ≥ 0.99 (R² cal. = 0.99861; root mean square error of cross-validation [RMSEC] = 2.04; R² val. = 0.99803; root mean square error of prediction [RMSEP] = 2.84; root mean square error of cross-validation [RMSECV] = 2.44) suggesting that this method could be successfully applied in the routine analysis of buffalo milk composition, providing rapid screening for possible adulteration with cow's milk at no additional cost.

• 한국토양비료학회지
• /
• 제43권3호
• /
• pp.374-383
• /
• 2010

본 연구에서는 기상조건에 영향을 받지 않고 레이더산란 측정을 할 수 있는 X-band 안테나 기반 자동관측 시스템을 구축하였다. 이 시스템을 이용하여 벼 생육시기에 따른 편파별 후방산란계수 변화와 벼 생육인자 변화를 관측하고, 후방산란계수와 벼 생육인자와의 관계를 분석을 통해 최적조건의 후방산란계수를 이용한 벼 생육을 추정하였다. 벼 생육시기에 후방산란계수 변화를 관측해 본 결과 생육초기에는 VV-편파가 HH, HV/VH-편파 보다 후방산란계수가 높게 나타났고, 모든 편파별 후방산란계수가 벼 유수형성기 (7월 말경)까지 증가하다가 그 후 감소 한 후 9월 초순이후 다시 증가하는 dual-peak 현상을 뚜렷이 나타났다. 동시에 생육시기에 따른 생체중, 이삭 건물중, 엽면적지수, 초장 등 벼 생육인자들의 생육 변화를 관측해 보았는데 생체중, 엽면적지수, 초장은 6월 중순부터 7월 하순까지 편파별 후방산란계수와의 변화 경향이 비슷하게 나타났고, 이삭 건물중의 경우 특히 VV-편파 후방산란계수가 9월 초순에서 10월 초순까지 변화 경향이 동일하게 나타났다. 편파별 후방산란계수와 벼 생육인자와의 상관관계를 분석한 결과 엽면적지수, 생체중은 6월 중순 (DOY 168)부터 7월 하순 (DOY 209) 시기에 HH-편파 후방산란 계수와 상관관계가 높았고, 초장은 같은 시기에 VV-편파 후방산란계수와 관계가 높게 나타났다. 이삭 건물중의 경우 벼 출수기가 끝나고 결실기로 접어드는 9월 초순 (DOY 244) 부터 10월 초순 (DOY 276) 시기에 VV-편파 후방산란계수와 상관관계가 높게 나타났다. 이 결과를 바탕으로 벼 생육인자와 상관이 높게 나타난 편파별 후방산란계수를 이용하여 벼 생육을 추정하였다. 엽면적지수는 HH-편파 후방산란계수를 이용하여 2007년도 실측값과 2008년도 추정 경험 모형을 비교해본 결과 비교적 오차가 작았고 (RMSE=0.43), 상관관계가 높은 HH-편파 후방산란계수를 이용하여 2007년도 생체중 실측값과 생체중 추정 모형 (2008년도)을 비교해 본 결과 RMSE가 41.0 g $m^{-2}$ 으로 비교적 작은 오차를 보여 생체중 추정 모형의 유효성이 높다는 것이 증명되었다. 또한 초장의 경우 실측값 (2007년)과 초장 추정 모형 (2008년)을 비교 분석한 결과 오차 범위가 비교적 작게 나타났고 (RMSE=6.93 cm), VV-편파 후방산란계수를 이용해 얻은 이삭 건물중 추정 경험 모형 (2008년도)과 2007년도 이삭 건물중 실측값과의 관계를 통해 추정식을 검증한 결과 RMSE=0.35 g/m2 을 보여 이삭 건물중 추정모형의 유효성이 높다는 것이 증명되었다. 본 연구결과에서는 Kim et al. (2009)이 일정한 간격을 두고 수동조건으로 관측한 결과와 비교해서 벼 생육시기에 따른 편파별 후방산란계수 변화 경향이 뚜렷하게 나타났고, 이 후방산란계수를 이용하여 벼 생육인자와의 관계 및 추정 결과에서도 기존 결과보다 상관관계 및 생육추정 모형 유효성이 높게 나타났다. 본 연구 결과를 통해 X-band 산란계 자동측정 시스템을 이용하여 벼 생육을 예측 할 수 있음을 확인하였다.