• Title/Summary/Keyword: Reference pattern

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Development of New Holography System for Measurments of Particle Velocities Using Separation of Images (이미지 분리를 이용한 입자 속도 측정을 위한 홀로그래피 시스템의 개발)

  • Kang, B.S.;Poulikakos, D.
    • Journal of ILASS-Korea
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    • v.2 no.2
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    • pp.16-23
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    • 1997
  • In this research a novel two-reference-beam double pulse holographic technique for the measurments of particle sizes and velocities was developed. This holographic method features the capability of separation of the first and second particle images by using two reference beams instead of one and the change of the polarization direction of laser light. The developed holographic system was tested through the measurements of droplet sizes and velocities in the spray created by two high speed impinging jets. The overall spray pattern clearly revealed the inherent wave nature. Smaller and faster droplets were generated with larger impingement angle, higher jet velocity. and smaller orifice diameter.

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DC-Link Voltage Unbalance Compensation of Reactive Power Compensator using Multi-level Inverter (멀티레벨 인버터를 이용한 무효전력 보상장치에서의 DC-Link 전압 불평형 보상)

  • Kim, Hyo-Jin;Jung, Seung-Ki
    • The Transactions of the Korean Institute of Power Electronics
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    • v.18 no.5
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    • pp.422-428
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    • 2013
  • Recently, we use a static synchronous compensator(STATCOM) with cascaded H-bride topologies, because it is easy to increase capacity and to reduce total harmonic distortion(THD). When we use equipment for reactive power compensation, dc-link voltage unbalances occur from several reasons although loads are balanced. In the past, switching pattern change of single phase inverter and reference voltage magnitude change of inverter equipped with power sensor have been used for dc-link voltage balance. But previous methods are more complicated and expensive because of additional component costs. Therefore, this paper explains reasons of dc-link voltage unbalance and proposes solution. This solution is complex method that is composed of reference voltage magnitude change of inverter without additional hardware and shifted phase angle of inverter reference voltages change. It proves possibility through 1000[KVA] system simulation.

Temperature Classification of Heat-treated Metals using Pattern Recognition of Ultrasonic Signal (초음파 신호의 패턴 인식에 의한 금속의 열처리 온도 분류)

  • Im, Rae-Muk;Sin, Dong-Hwan;Kim, Deok-Yeong;Kim, Seong-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.12
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    • pp.1544-1553
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    • 1999
  • Recently, ultrasonic testing techniques have been widely used in the evaluation of the quality of metal. In this experiment, six heat-treated temperature of specimen have been considered : 0, 1200, 1250, 1300, 1350 and 1387$^{\circ}C$. As heat-treated temperature increases, the grain size of stainless steel also increases and then, eventually make it destroy. In this paper, a pattern recognition method is proposed to identify the heat-treated temperature of metals by evidence accumulation based on artificial intelligence with multiple feature parameters; difference absolute mean value(DAMV), variance(VAR), mean frequency(MEANF), auto regressive model coefficient(ARC), linear cepstrum coefficient(LCC) and adaptive cepstrum vector(ACV). The grain signal pattern recognition is carried out through the evidence accumulation procedure using the distances measured with reference parameters. Especially ACV is superior to the other parameters. The results (96% successful pattern classification) are presented to support the feasibility of the suggested approach for ultrasonic grain signal pattern recognition.

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A Study on the Circulation System on accordance with the Merchandise in Discount Store - with reference to the spatial configuration and the VMD pattern - (대형아트의 상품구성에 따른 동선체계의 특징에 관한 연구 - 공간구조와 공간연출의 특성을 기준으로 -)

  • Kim, Sae-Eun;Moon, Jung-Mook
    • Korean Institute of Interior Design Journal
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    • v.17 no.6
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    • pp.137-142
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    • 2008
  • Since mid 1990s, the domestic market in Korea has been changing drastically especially in the field of discount stores. The competition among this market is more severe and the consuming pattern is also changed. This study is to examine the correlation between the customer's circulation and the spatial configuration by using Space Syntax and VMD pattern through the MD plan of each floor in Discount store. Throughout this study, it tries to find out the Quantitative analysis among three factors - the customer's circulation, spatial configuration and VMD investigation. The pattern of customer's circulation appears differently according to the identity of customer and store layout, but with the result, customer's circulation system is in accordance with the floor layout in the store. In result of the study, the circulation of the customer was found to have a close relationship with spatial structure that is composed by the MD pattern in a discount store in the area of food section. Also, the circulation system in the rest area except food section is more affected by the VMD pattern rather than spatial structure.

Analysis of characteristics of YouTube video contents for the development of pattern drafting video (패턴제작 교육용 영상콘텐츠 개발을 위한 유튜브 영상 현황 분석)

  • Kang, Yeo Sun
    • The Research Journal of the Costume Culture
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    • v.27 no.6
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    • pp.599-614
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    • 2019
  • The aim of this study to provide basic reference data for the development of video contents used in pattern drafting education and to explore the possibility of utilizing YouTube videos in such education. Subject videos were selected using the number of views. A total of 596 videos and 28 channels were analyzed for the period July to September 2019 and the results are as follows. With regard to content, there were 27 pattern drafting items, the majority being dress, pants, skirt, blouse and sleeve drafting, although high-level content such as cowl, bustier, corset patterns were also available. Therefore, there is a high likelihood that YouTube videos could be used as educational material, especially as supplementary references to provide specific examples and easy explanations for difficult concepts or method, for students majoring in this field. However, as most videos currently focus on a few items, expanding video content to features a wider variety of clothing items at different levels is necessary. With regard to video length, it mostly ranged from 10 to 15 minutes. It is not advisable to create lengthy lecture-style videos expounding on different principles or variations in pattern drafting when developing educational video material.

The Quality of a Traditional Dietary Pattern in Relation to Metabolic Syndrome in Elderly South Koreans

  • Oh, Chorong;No, Jaekyung
    • Journal of Obesity & Metabolic Syndrome
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    • v.27 no.4
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    • pp.254-261
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    • 2018
  • Background: The most beneficial dietary pattern in managing metabolic syndrome (MetS) in the elderly has not been ascertained. The aim of this study is to classify dietary patterns and to examine associations between dietary pattern, MetS and body composition in elderly Koreans. Methods: This study was conducted among Koreans 65 years or older using data from the Korea National Health and Nutrition Examination Survey in 2009. A total of 1,567 study subjects were included. All statistical analyses were conducted using SPSS version 20.0 and dietary patterns were classified by cluster analysis. Results: There were three dietary patterns derived by cluster analysis in this study. We observed that most South Korean elderly still maintain a traditional dietary pattern. Dietary patterns were classified as balanced (31%), imbalanced (40%), or very imbalanced (30%), with the majority of subjects having an unbalanced diet pattern in which their total energy and nutrient intake was insufficient compared with the Dietary Reference Intake for Koreans. Those in the very imbalanced group had a ratio of macronutrients (carbohydrates:fats:protein) of 81.15:7.18:11.50 and a 54% higher likelihood of having hypertriglyceridemia (P=0.025) compared with those in the balanced group. Conclusion: The current findings indicate that the diets of South Korean elderly are nutritionally imbalanced, including high carbohydrate consumption, which confers a high risk hypertriglyceridemia. These findings highlight the effect of nutritional imbalance in elderly with MetS.

Performance analysis of EIT bladder monitoring system according to input current patterns (주입전류 패턴에 따른 EIT 방광 모니터링 시스템의 성능분석)

  • Han, You-Jung;Khambampati, Anil Kumar;Kim, Kyung-Youn
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.164-172
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    • 2019
  • Current clinical methods for diagnosing urination disorder are invasive, expensive, and very inconvenient to perform continuous monitoring. EIT is a non-invasive technique that injects electrical current through an external electrodes and measures the induced voltage to visualize the internal electrical (impedance) characteristics, which makes it possible to monitor bladder conditions with low cost. The signal characteristics of the measured voltage data changes according to the current pattern injected through the electrode and affects reconstruction performance. In this paper, image reconstruction performance is compared and analyzed according to the injected current patterns to maximize the sensitivity to the variation of bladder size.

Two-phase flow pattern online monitoring system based on convolutional neural network and transfer learning

  • Hong Xu;Tao Tang
    • Nuclear Engineering and Technology
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    • v.54 no.12
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    • pp.4751-4758
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    • 2022
  • Two-phase flow may almost exist in every branch of the energy industry. For the corresponding engineering design, it is very essential and crucial to monitor flow patterns and their transitions accurately. With the high-speed development and success of deep learning based on convolutional neural network (CNN), the study of flow pattern identification recently almost focused on this methodology. Additionally, the photographing technique has attractive implementation features as well, since it is normally considerably less expensive than other techniques. The development of such a two-phase flow pattern online monitoring system is the objective of this work, which seldom studied before. The ongoing preliminary engineering design (including hardware and software) of the system are introduced. The flow pattern identification method based on CNNs and transfer learning was discussed in detail. Several potential CNN candidates such as ALexNet, VggNet16 and ResNets were introduced and compared with each other based on a flow pattern dataset. According to the results, ResNet50 is the most promising CNN network for the system owing to its high precision, fast classification and strong robustness. This work can be a reference for the online monitoring system design in the energy system.

CCR : Tree-pattern based Code-clone Detector (CCR : 트리패턴 기반의 코드클론 탐지기)

  • Lee, Hyo-Sub;Do, Kyung-Goo
    • Journal of Software Assessment and Valuation
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    • v.8 no.2
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    • pp.13-27
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    • 2012
  • This paper presents a tree-pattern based code-clone detector as CCR(Code Clone Ransacker) that finds all clusterd dulpicate pattern by comparing all pair of subtrees in the programs. The pattern included in its entirely in another pattern is ignored since only the largest duplicate patterns are interesed. Evaluation of CCR is high precision and recall. The previous tree-pattern based code-clone detectors are known to have good precision and recall because of comparing program structure. CCR is still high precision and the maximum 5 times higher recall than Asta and about 1.9 times than CloneDigger. The tool also include the majority of Bellon's reference corpus.

Development on the Questionnaire of Cold-Heat Pattern Identification Based on Usual Symptoms for Health Promotion - Focused on Agreement Study (건강 증진을 위한 평소 증상 기반의 한열변증 설문지 개발 - 일치도를 중심으로)

  • Bae, Kwang-Ho;Yoon, Youngheum;Yeo, Minkyung;Kim, Ho-Seok;Lee, Youngseop;Lee, Siwoo
    • Journal of Society of Preventive Korean Medicine
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    • v.20 no.2
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    • pp.17-26
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    • 2016
  • Objectives : We presented the results of reliability study in advance, and analyzed agreement between Korean medicine doctors(KMDs)' diagnosis and cold-heat pattern identification questionnaire(CHPI)'s diagnosis. Methods : This survey was conducted from May 16 to 17, 2015. The subjects were 93 adults living in rural society. Diagnosis of CHPI was performed by 2 KMDs who have clinical experience more than 5 years. The KMDs' diagnosis was set as a reference index, and then we compare 23 items(cold pattern 11 items and heat pattern 12 items) of CHPI questionnaire and 15 items(cold pattern 8 items and heat pattern 7 items) that were brief form of it. We had cut-off value by standard of KMDs' diagnosis using receiver operating characteristic-curve(ROC-curve), with which we calculated agreement including kappa value. Correlation analysis between CHPI evaluation score by KMDs and by the questionnaire was fulfilled as well. Results : Agreement about 11 and 8 cold pattern items showed 87.1% together, and the value of kappa each recorded 0.742 and 0.741. Agreement about 12 and 7 heat pattern items suggested 81.7% and 78.5%, and the value of kappa showed 0.634 and 0.570. Correlation coefficients were 0.803 of 11 items and 0.761 of 8 items about cold pattern. In addition, correlation coefficients were 0.789 of 12 items and 0.767 of 7 items about heat pattern. The significant probability (p-value) was under 0.001. Conclusions : We have developed CHPI questionnaire involving reliability and agreement based on usual symptoms, and hope additional complements so that Korean medicine diagnostics and Korean preventive medicine would be improved.