• 제목/요약/키워드: Experimental Units

검색결과 771건 처리시간 0.032초

제 7차 교육과정 10학년 과학 교과에 포함된 환경단원의 탐구요소 분석 (An Analysis on Inquiry Elements of Environmental Units in the 10th Grade Science Textbooks, the 7th Curriculum)

  • 오강호;고영구
    • 한국환경교육학회지:환경교육
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    • 제17권1호
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    • pp.77-89
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    • 2004
  • This study aims to consider interrelations and reasonability to inquiry elements of environment units in 10th Science textbooks of 7th curriculum on the basis of their inquiry contexts, processes and activities. Frequency of inquiry contexts is 59.9% of the highest value in natural environment context but is 4.0% of the lowest one in techno-industrial context. Measurements, inferences, predictions, experiments, data-interpretations, correlations, conclusionreveals in inquiries are in all the textbooks, but observations and classifications, hypothesis generations, controlling variables, experimental designs and generalizations are not in some textbooks. Discussions, experiments, investigations in inquiry activities are included in all the textbooks. However, inspections are not appeared in the all the books. Based on the above results, social and techno-industrial inquiry contexts in the varied scopes are necessary in the environment curricula with a unified direction. Inquiry processes with pro-environmental behaviors as a last goal might be given into the curricula, having tasks that could be understand unified inquiries. In addition, inspections with effectiveness might be thrown into the scene of education.

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Secondary Voltage Control for Reactive Power Sharing in an Islanded Microgrid

  • Guo, Qian;Wu, Hongyan;Lin, Liaoyuan;Bai, Zhihong;Ma, Hao
    • Journal of Power Electronics
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    • 제16권1호
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    • pp.329-339
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    • 2016
  • Owing to mismatched feeder impedances in an islanded microgrid, the conventional droop control method typically results in errors in reactive power sharing among distributed generation (DG) units. In this study, an improved droop control strategy based on secondary voltage control is proposed to enhance the reactive power sharing accuracy in an islanded microgrid. In a DG local controller, an integral term is introduced into the voltage droop function, in which the voltage compensation signal from the secondary voltage control is utilized as the common reactive power reference for each DG unit. Therefore, accurate reactive power sharing can be realized without any power information exchange among DG units or between DG units and the central controller. Meanwhile, the voltage deviation in the microgrid common bus is removed. Communication in the proposed strategy is simple to implement because the information of the voltage compensation signal is broadcasted from the central controller to each DG unit. The reactive power sharing accuracy is also not sensitive to time-delay mismatch in the communication channels. Simulation and experimental results are provided to validate the effectiveness of the proposed method.

EP Based PSO Method for Solving Multi Area Unit Commitment Problem with Import and Export Constraints

  • Venkatesan, K.;Selvakumar, G.;Rajan, C. Christober Asir
    • Journal of Electrical Engineering and Technology
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    • 제9권2호
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    • pp.415-422
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    • 2014
  • This paper presents a new approach to solve the multi area unit commitment problem (MAUCP) using an evolutionary programming based particle swarm optimization (EPPSO) method. The objective of this paper is to determine the optimal or near optimal commitment schedule for generating units located in multiple areas that are interconnected via tie lines. The evolutionary programming based particle swarm optimization method is used to solve multi area unit commitment problem, allocated generation for each area and find the operating cost of generation for each hour. Joint operation of generation resources can result in significant operational cost savings. Power transfer between the areas through the tie lines depends upon the operating cost of generation at each hour and tie line transfer limits. Case study of four areas with different load pattern each containing 7 units (NTPS) and 26 units connected via tie lines have been taken for analysis. Numerical results showed comparing the operating cost using evolutionary programming-based particle swarm optimization method with conventional dynamic programming (DP), evolutionary programming (EP), and particle swarm optimization (PSO) method. Experimental results show that the application of this evolutionary programming based particle swarm optimization method has the potential to solve multi area unit commitment problem with lesser computation time.

Detection and Localization of Image Tampering using Deep Residual UNET with Stacked Dilated Convolution

  • Aminu, Ali Ahmad;Agwu, Nwojo Nnanna;Steve, Adeshina
    • International Journal of Computer Science & Network Security
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    • 제21권9호
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    • pp.203-211
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    • 2021
  • Image tampering detection and localization have become an active area of research in the field of digital image forensics in recent times. This is due to the widespread of malicious image tampering. This study presents a new method for image tampering detection and localization that combines the advantages of dilated convolution, residual network, and UNET Architecture. Using the UNET architecture as a backbone, we built the proposed network from two kinds of residual units, one for the encoder path and the other for the decoder path. The residual units help to speed up the training process and facilitate information propagation between the lower layers and the higher layers which are often difficult to train. To capture global image tampering artifacts and reduce the computational burden of the proposed method, we enlarge the receptive field size of the convolutional kernels by adopting dilated convolutions in the residual units used in building the proposed network. In contrast to existing deep learning methods, having a large number of layers, many network parameters, and often difficult to train, the proposed method can achieve excellent performance with a fewer number of parameters and less computational cost. To test the performance of the proposed method, we evaluate its performance in the context of four benchmark image forensics datasets. Experimental results show that the proposed method outperforms existing methods and could be potentially used to enhance image tampering detection and localization.

신경계 중환자에게 적용한 섬망 예방중재의 효과 (Effects of Delirium Prevention Interventions for Neurocritical Patients)

  • 이민지;윤선희;최경옥;성선숙;이선미;강재진
    • 기본간호학회지
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    • 제25권2호
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    • pp.109-119
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    • 2018
  • Purpose: The purpose of this study was to investigate the effects of a delirium prevention intervention for patients in neurology and neurosurgery intensive care units (ICUs). Methods: This study was a quasi-experimental study. Participants were 87 patients. The experimental group was provided with nonpharmacologic and multicomponent delirium prevention interventions, consisting of regular delirium assessment, improvement in orientation, early therapeutic intervention, and environmental interventions. The control group was provided with routine intensive care. Data were analyzed using $x^2$ test, Fisher's exact test, and t-test. Results: Both groups were homogeneous. The incidence of delirium and length of hospitalization were significantly lower in the experimental group compared to the control group. ICU stay, mortality and unplanned extubation were lower in the experimental group compared to the control group, but there was no significant difference. Conclusion: Findings indicate that the delirium prevention intervention is effective in reducing incidence of delirium and length of hospitalization. Therefore, this intervention should be helpful in preventing delirium in neurology and neurosurgery ICUs and can be used as a guide in the prevention of delirium in neurological diseases's patients.

Treatments Effect on Biological Values of Defatted Rice Polishings

  • Khalique, Anjum;Lone, K.P.;Khan, A.D.;Pasha, T.N.
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권2호
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    • pp.209-216
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    • 2006
  • Defatted rice polishings (DRP) was subjected to chemical treatments i.e., 0.4 N HCl, and 6% $H_2O_2$, with or without physical treatment i.e. extrusion cooking. The treated DRP was evaluated chemically and biologically using male broiler chicks (108) of approximately uniform weight, selected out of 220 chicks, previously fed on commercial diets for 7 days as a settlement period. The chicks were then divided into 36 experimental units of 3 chicks each. Each experimental diet was randomly allotted to three experimental units and fed for 10 days to broiler chicks. The experimental diets were designated as A (Commercial), B (10% HCl treated DRP), C (20% HCl treated DRP), D (10% HCl plus extruded DRP), E (20% HCl plus extruded DRP), F (10% $H_2O_2$ DRP) and G (20% $H_2O_2$ DRP), H (10% $H_2O_2$ plus extrusion DRP) and I (20% $H_2O_2$ plus extrusion DRP), J (10% untreated DRP), K (20% untreated DRP) and L (Protein free). The birds fed on diet L were used to measure the endogenous nitrogen loss. The biological evaluations of diets containing differently treated DRP were compared with a commercial feed and feeds containing untreated defatted rice polishings. It was observed that these treatments liberated bound nutrients, making them more accessible to the normal digestive enzymes and increased their apparent nutrient availability. This process probably also detoxified the anti-nutritive factors i.e. phytates, lectin, trypsin inhibitor present in DRP. The results of the feeding trials revealed that diets containing 6% $H_2O_2$ treated DRP showed better weight gain, feed consumption and utilization, protein efficiency and digestibility, biological value and net protein utilization than all other treatments.

구성주의 접근의 요리활동이 유아의 과학적 태도와 창의성에 미치는 영향 (The Effects of a Constructivist Approach to Cooking Activities on Young Children's Scientific Attitudes and Creativity)

  • 박고운;김선영
    • 아동학회지
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    • 제32권1호
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    • pp.141-156
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    • 2011
  • This research centers around an experiment conducted to determine the relative effectiveness of constructivist cooking activities as compared to traditional cooking activities for young children. Forty-six children, aged five years in two kindergarten classes were assigned to a experimental and comparative group. The experimental and comparative group participated in 12 units. The experimental group participated in the constructivist cooking activities, while the comparative group participated in the traditional cooking activities. Analysis of covariance revealed significant differences between the mean scores of the two groups on the posttests for scientific attitudes and creativity, indicating that the children in the experimental group performed significantly better on the tests than the children in the comparative group. The results of this study suggest that such constructivist cooking activities are able to improve the scientific attitudes and creativity of young children.

Variations in the Thermal Performance of R22 and R410A Refrigeration Systems Depending on Operation Conditions

  • Jeong, Ji-Hwan;Kweon, Young-Chel;Chang, Keun-Sun
    • International Journal of Air-Conditioning and Refrigeration
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    • 제12권1호
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    • pp.10-20
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    • 2004
  • Experiments have been conducted in order to make comparisons of characteristics of a R410a cycle with a R22 cycle in terms of cooling capacity and coefficient of performance (COP). The parameters examined in the present work include air flow rate, indoor and outdoor air temperatures, and indoor relative humidity. These two refrigeration cycles constructed for this study share all components except compressor, accumulator, oil separator, and piping. The measurements were made using a psychrometric calorimeter. The experimental results show that the R410A cycle has several advantages for indoor units while the R22 cycle yields better performance for outdoor units.

Korean Broadcast News Transcription Using Morpheme-based Recognition Units

  • Kwon, Oh-Wook;Alex Waibel
    • The Journal of the Acoustical Society of Korea
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    • 제21권1E호
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    • pp.3-11
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    • 2002
  • Broadcast news transcription is one of the hardest tasks in speech recognition because broadcast speech signals have much variability in speech quality, channel and background conditions. We developed a Korean broadcast news speech recognizer. We used a morpheme-based dictionary and a language model to reduce the out-of·vocabulary (OOV) rate. We concatenated the original morpheme pairs of short length or high frequency in order to reduce insertion and deletion errors due to short morphemes. We used a lexicon with multiple pronunciations to reflect inter-morpheme pronunciation variations without severe modification of the search tree. By using the merged morpheme as recognition units, we achieved the OOV rate of 1.7% comparable to European languages with 64k vocabulary. We implemented a hidden Markov model-based recognizer with vocal tract length normalization and online speaker adaptation by maximum likelihood linear regression. Experimental results showed that the recognizer yielded 21.8% morpheme error rate for anchor speech and 31.6% for mostly noisy reporter speech.

가로주행식 케미게이션 시스템의 개발 (Development of a Linear Chemigation System)

  • 구영모;배영환;박금주;정상옥
    • Journal of Biosystems Engineering
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    • 제26권2호
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    • pp.93-104
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    • 2001
  • A linear chemigation system, integrating agrichemical appication units of pesticide and fertilizer into an irrigation system, was selected as a suitable model for the cost savings in farm management and automation. Technical designs were conducted in the areas of structure, power, drive, control, and hydraulic systems. An experimental farm was sectioned into the fields of 40m by 200m and systemized with the linear-move chemigation system of 36m in span. The chemigation system consisted of a base unit monitoring and controlling overall operation, and a driving unit traveling linearly and injecting agrichemicals. Monitoring and interlocking systems were utilized against unexpected malfunctions of power, injection and drive systems using radio freuency modems between the units. The system can be also modified to various farm sizes and stationary systems of indoor and outdoor.

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