• Title/Summary/Keyword: 유사 이미지

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Flame Interaction with Shear Layer Flow in the Post Chamber of Hybrid Rocket (하이브리드 로켓 후연소실 전단유동과 연소반응의 상호 간섭)

  • Moon, Young Joo;Lee, Changjin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.7
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    • pp.585-592
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    • 2016
  • Visualization was done by using $CH^*$ chemiluminescence images and PMT measurements in order to understand the origin of fluctuating pressure and chemical luminosity at about 500 Hz frequency even in stable combustion, which was observed in recent experimental tests, and to find the physical correlation leading to Low Frequency Instability(LFI) in terms of phase angle. In stable combustion, chemical reactions are distributed along the shear layer flow showing a negative coupling(about 180 degree in phase angle) with combustion pressure. However, phase difference is shifted to a positive coupling showing less than 90 degree in unstable case. Also a periodic change in the distribution of chemical reactions is observed along with local flame extinction and the appearance of big scale vortex flow. In the transition to LFI, local flame extinction and small vortex flow start to appear in a row. As seen in the bluff body wake in reactive flow, the periodic appearance of vortex flow seems to share the same physical process of BVK(Bernard Von Karman) instability generation. Thus, the appearance of local extinction in 500 Hz fluctuations is gradually amplified to complete extinctions of about 20 Hz, and it leads into LFI.

Experimental Study on Dilution Effect of Exhaust Gas in SNG Combustion on a Model Gas Turbine (가스터빈에서 SNG 연료 조성에 대한 희석제의 배기배출물 저감효과에 대한 실험적 연구)

  • Joo, Seongpil;Yoon, Jisu;Kim, Jeongjin;Kim, Seongheon;Yoon, Youngbin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.7
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    • pp.603-610
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    • 2016
  • This paper describes experimental results about emission and NOx reduction of dilution effect (Nitrogen and carbon dioxide) about various fuel compositions of synthetic natural gas (SNG). Combustion experiment was performed to investigate the combustion characteristics for SNG with various hydrogen ratio in SNG, heat input and equivalence ratio in a partially premixed model gas turbine combustor. NOx emission was similar to each hydrogen ratio and flame characteristics was investigated from OH chemiluminescence images. There was a singularity of CO emission in stoichiometric condition and it can be identified using OH chemiluminescence intensity. In addition, dilution effect was studied in using nitrogen and carbon dioxide as diluent to reduce the NOx emission. Carbon dioxide diluent was more effective to NOx reduction than nitrogen diluent because of its high diluent specific heat and its heat capacity.

당류산업

  • 임재각
    • Food Industry
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    • s.181
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    • pp.38-67
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    • 2004
  • 예로부터 인간은 단맛에 강한 욕구를 가지고 있었다. 따라서 설탕, 포도당, 과당 등 단맛이 강한 감미료를 선호하여 왔고, 현재까지도 식품 제조시 가장 널리 사용되고 있다. 그러나 최근에는 국민의 건강에 대한 관심이 고조 되고 설탕으로 대표되는 전통적인 일반 감미료의 충치, 비만, 당뇨병 유발 등의 부정적인 측면이 부각되고 있을 뿐만 아니라, 식품에 대한 건강 기능성이 강조되면서 기능성 감미료가 주목 받고 있다. 특히 고도의 경제성장 및 국민 소득의 향상에 따라 차별화된 기능성 감미료의 생산을 요구하는 실정이다. 이와 관련하여, 현재 식품 산업계에서는 올리고당류, 당알콜류, 고감미 감미료류 등에 많은 관심을 가지고 연구 개발에 집중하고 있다. 올리고당류의 대표적인 제품은 프락토올리고당, 갈락토올리고당, 이소말토올리고당 등이다. 현재 올리고단 시장은 성숙기로서 성장속도가 둔화되고 있으나, 최근 American Association of Cereal Chemists(AACC)등 세계적인 협회에서 수용성 식이섬유를 다당류, 올리고당, 리그닌 등을 포함하여 새롭게 정의하였고 이에 따라 해외에서는 프락토올리고당을 중심으로 수용성 식이섬유로 용도 사용이 가능하게 되었을 뿐만 아니라, 식이섬유로 표기도 가능하게 되어 수요가 증가할 것으로 예상된다. 국내에서는 아직 올리고당을 식이섬유로 사용하지는 못하고 있으나, 식품 공전 개정을 통해 식이섬유로 표기 가능하도록 수정될 전망이다. 당알콜류는 솔비톨 및 자일리톨이 주류를 이루고 있다. 솔비톨은 시장에 가장 먼저 소개된 당알콜류인데 저가여서 그동안 가장 큰 시장을 형성하고 있었으나 최근 3년 동안 자일리톨껌이 최대의 히트 상품이 되면서 자일리톨이 급성장하였다. 그 외에는 만니톨, 에리스리톨, 말티톨, 이소말트 등이 있다. 최근에는 말티톨을 중심으로 다양한 응용 연구 및 이소말트 및 에리스리톨 등을 생산 판매하고 있는 다국적 기업의 판촉 활동 등으로 당알콜류 시장의 새로운 변화가 예상된다. 고감미 감미료류는 스테비오사이드와 아스파탐이 주류를 이루고 있었지만, 최근 아세설팜 K 및 수크랄로스가 잇따라 식품으로써 사용 허가를 받으면서 시장이 재편되고 있다. 하지만, 해외에 비하여 국내의 고감미 감미료 시장은 매우 작고 성장률도 낮은 편인데 그 이유로는 국민 정서상 천연이 아닌 합성에 대한 부정적 인식과 맛에 대한 거부감 때문인 것으로 생각된다. 이와 관련하여 최근에는 다양한 감미질 및 Multi sweetener system 연구를 통해 설탕과 유사한 맛을 내는 혼합 기술 개발에 관한 연구가 진행되고 있다. 따라서 향후에는 해외의 선진국과 같이 고감미 감미료 시장도 점차적으로 확대될 것으로 예상된다. 기타 대체 감미료로는 타가토스, 트레할로스, 아라비노스 등이 있다. 이중에서 특히 해외에서 크게 기대를 모으고 있는 타가토스는 최근 국내 인증을 받아 시장 진출을 준비 중에 있다. 아라비노스는 양질의 감미를 갖는 천연 펜토오스인데 연구용 시약 이외에는 지금까지 거의 이용되지 않았다. 그러나 최근 아라비노스가 설탕의 소화흡수를 선택적으로 억제한다는 흥미 있는 결과가 임상 및 동물실험에서 확인되어 향후 제품으로써 개발을 기대할 수 있게 되었다. 이들 감미료는 기존 설탕이 가지는 문제점을 많은 부분 극복할 것으로 여겨지며, 이로 인해 수요는 점차 증가할 것으로 생각되며, 높은 경제적 부가 가치를 창출할 것으로 예상되어 진다. 생산 기술 적인 측면에서 건강 지향적 천연소재 감미료에 대한 선호가 날로 증가하는 추세에 따라 기존에 주로 사용되었던 화학합성법보다는 천연 이미지의 생물공학적인 방법에 의한 감미료 생산이 각광을 받을 것으로 예상된다. 생물공학적인 방법을 감미료 소재 개발에 응용하게 되면, 기존에 사용되었던 화학합성법 등이 가지는 환경적인 문제, 반응 부산물 생성에 따른 분리, 정제에서의 비용증가 등의 문제점을 해결할 수 있을 것으로 여겨지며, 고정화 방법의 도입 등을 통해 생산성 향상을 도모할 수 있다. 본 장에서는 감미료 소재 개발에 건강 지향적 국민 정서를 반영하고, 국내외 감미료 시장의 흐름을 파악하여 당류 산업의 발전적인 변화에 대처하고자 하였으며, 이를 통해 당류산업의 고부가가치 첨단산업으로서의 육성방안을 논의하고자 하였다.

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A Study on Person Re-Identification System using Enhanced RNN (확장된 RNN을 활용한 사람재인식 시스템에 관한 연구)

  • Choi, Seok-Gyu;Xu, Wenjie
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.17 no.2
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    • pp.15-23
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    • 2017
  • The person Re-identification is the most challenging part of computer vision due to the significant changes in human pose and background clutter with occlusions. The picture from non-overlapping cameras enhance the difficulty to distinguish some person from the other. To reach a better performance match, most methods use feature selection and distance metrics separately to get discriminative representations and proper distance to describe the similarity between person and kind of ignoring some significant features. This situation has encouraged us to consider a novel method to deal with this problem. In this paper, we proposed an enhanced recurrent neural network with three-tier hierarchical network for person re-identification. Specifically, the proposed recurrent neural network (RNN) model contain an iterative expectation maximum (EM) algorithm and three-tier Hierarchical network to jointly learn both the discriminative features and metrics distance. The iterative EM algorithm can fully use of the feature extraction ability of convolutional neural network (CNN) which is in series before the RNN. By unsupervised learning, the EM framework can change the labels of the patches and train larger datasets. Through the three-tier hierarchical network, the convolutional neural network, recurrent network and pooling layer can jointly be a feature extractor to better train the network. The experimental result shows that comparing with other researchers' approaches in this field, this method also can get a competitive accuracy. The influence of different component of this method will be analyzed and evaluated in the future research.

Approach on the Emotional Relationship between Consumers and Brands based on Triangular Theory of Love -With focus on Mobile Phone Service and Product Brands- (소비자-브랜드 감성적 관계에 대한 사랑의 삼각이론적 접근 -이동통신 서비스와 단말기 브랜드를 중심으로-)

  • Choi, Won-Joo
    • Korean journal of communication and information
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    • v.44
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    • pp.7-43
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    • 2008
  • This study aims to identify a new direction in the consumer-brand relationship by quantitatively approaching from the psychological aspect consumers' brand love, which is the most powerful strategic element in forming an emotional consumer-brand relationship. What significance does brand love have in a consumer-brand relationship? Brand love is the most fundamental in the emotional consumer-brand relationship. Through brand ownership, consumers add meaning to their lives, and love brands by expressing themselves. Love is a scale that understands consumer-brand relationship from the most interpersonal aspect and can be considered as the most essential element in an empathetic relationship. Consumers' brand love not only determines brand image and reliability but through brand loyalty, it also influences market competitiveness. In addition, as a medium that can overcome brand crisis, it serves as a turning point of the relationship and can enhance the strength of consumers' brand love. Under such generational and theoretical background, this study took a psychological approach on love in emotional consumer-brand relationship. Focusing on the most representative theory and classification of love, Sternberg's Triangular Theory of Love, types of brand love were examined. 552 questionnaires were distributed through a survey with mobile phone service and product brands, and a factor analysis was conducted. Types of brand love revealed through the results of this study were very similar to Sternberg's types of love, and it was found that the types of brand love varied based on product category. It can be suggested that the concept of brand love is an important strategic idea in brand communication.

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An Analysis of Science Magazine in the View of Infographic (인포그래픽 관점을 이용한 과학 잡지 분석)

  • Jeon, Seongsoo;Jung, Jinkyu;Park, Jong-Ho
    • Journal of The Korean Association For Science Education
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    • v.34 no.6
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    • pp.601-611
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    • 2014
  • The purpose of this study is to analyze the Korean science magazine, Science Donga providing scientific facts, phenomenons, and issues with infographic for the readers by time series analysis and to search for the application of infographic on the science education. The criteria for the infographic analysis of Science Donga consisted of three categories such as storytelling type, visual perception, and framework level because infographic presents complex information quickly and clearly by integrating various images, words, and graphics. We found that the articles emphasized by including image about science issue have been published from 1986 to 2014. Particularly, after 2008, the articles including infographic sharply rose. So we set up 2008 as $T_c$(Critical time point). The articles including infographic after 2008 have been more variously distributed and frequently used in storytelling types category such as location, time, number, connection, function, and process based infographic, in visual perception of Gestalt Theory such as proximity, similarity, continuation, and closure than before 2008. Lastly, in framework level category, location, time, number, and process based infographic mainly had total range level but function and connection based infographic changed in the framework level. The three features about storytelling type, visual perception, framework level are important changes to influence $T_c$ in the infographic analysis about Science Donga. Through the results of this study, we analyzed the feature of change on infographic from 1986 to 2014. Thus, we hope that the results suggest a basic criteria for making materials including infographic in science education.

A Study on the Influence of Apartment Brand Image on Occupancy Satisfaction (아파트 브랜드 이미지가 입주만족도에 미치는 영향 분석)

  • Kim, Dong-Il;Kang, Hee-Sam
    • Journal of the Korea Convergence Society
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    • v.9 no.3
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    • pp.241-247
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    • 2018
  • The purpose of this study is to investigate the relationship between the residential satisfaction and the residential satisfaction in the residential environment. For this study, we analyzed the main factors of occupancy satisfaction by integrating previous studies on brand and housing and purchase intention, developing a research model based on the theoretical study on occupancy satisfaction, and establishing a research hypothesis. The results of this study are as follows: First, the relationship between first brand image and occupancy satisfaction is statistically significant. Second, the relationship between residential satisfaction and residential satisfaction is significant. In addition, the relationship with prices acting as parameters is analyzed to be somewhat significant. Therefore, this study is expected to provide not only useful information in the relationship between apartment supplier and consumer, but also provide basic information on similar research. Therefore, this study is expected to provide not only useful information in the relationship between apartment supplier and consumer, but also provide basic information on similar research. However, due to limitations such as selection of control variables and analytical errors, future research should be conducted through development of more comprehensive and valid indicators.

Study of Sensor Technology Analysis and Site Application Model for 3D-based Global Modeling of Construction Field (건설 시공현장의 3D기반 광대역 모델링을 위한 Sensor 기술 분석과 향후 현장적용 모델 연구)

  • Kwon, Hyuk-Do;Koh, Min-Hyeok;Yoon, Su-Won;Kwon, Soon-Wook;Chin, Sang-Yoon;Kim, Yea-Sang
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2007.11a
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    • pp.938-942
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    • 2007
  • The importance of process improvement under construction has arisen from recent issue, lower productivity in the construction site. The various 3D modeling program is utilized in the procedure of construction as an alternative solution. However, it's still shortage of the consideration about a specific technical application. The purpose of the study in this paper is helpful to improve the productivity of construction site using 3D realization of constructing place as one of extensive modeling technologies, which leads to not only efficient management of construction site allowing people to check the real time situation in the place but also the revitalization of information flow about building process control and prgress, Therefore, I research into modeling algorithm and extensive construction site realization technology. 3D realization of building place would reduce the safety concerns by providing the real time information about construction site, and it could help to access easily to similar project through collecting and appling the database of sites. Furthermore it can be an opportunity to develop the procedure of production in construction industry and to upgrade the image of this field.

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Evaluation of Interior Factors in Gyunro-dang and Recommendations for Improvement -In 14 Facilities at Apartment Complex in Seoul- (경로당 실내환경 평가와 개선방안 -서울지역 아파트 단지 내 14개 시설을 중심으로-)

  • 천진희
    • Archives of design research
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    • v.17 no.3
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    • pp.353-362
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    • 2004
  • This research has been done to evaluate the interior environmental factors in Gyungro-dang to suggest the advanced recommendations for them. For this research, the essential interior elements influencing on elderly's behavior were examined with the developed checklist, the lighting and color conditions of main hall at 14 facilities in Seoul area were analysed, and 124 subjects staying at Gyungro-dang were participated in questionaire survey for color preferences. Results showed that 1.The average installation rate of 39 items in checklist was 59%, the mandatory items such as accessible dimension were considered, but several items related to mobility and safety were not properly installed. Therefore not only guiding handrail and floor block to destination but also elimination of obstacles should be reconsidered. 2.The average of illuminances was 289 Lux dose to standard 300 Lux, but lighting quality was too low to support the activities of elderly users. The lighting control devices, combined lighting sources, and suitable lighting techniques should be applied for those facilities. 3.Most facilities were predominantly in warm colors in hue, medium or high value, low saturation, and natural atmosphere with similarity harmony. The color applications in those facilities were not functional, but similar as color preferences for the elderly except overall atmosphere. It is recommendable to include contrast harmony with classic or romantic mood.

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A Study on the Droplet Formation of Liquid Metal in Water-Mercury System as a Surrogate of Molten Salt-Liquid Metal System at Room Temperature (용융염-액체금속 계의 대용물인 물-수은 계에서 액체금속 액적의 생성에 대한 연구)

  • Kim, Yong-il;Park, Byung Gi
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.16 no.2
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    • pp.165-172
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    • 2018
  • As an approach for estimation of the droplet size in the molten salt-liquid metal extraction process, a droplet formation experiment at room temperature was conducted to evaluate the applicability of the Scheele-Meister model with water-mercury system as a surrogate that is similar to the molten salt-liquid metal system. In the experiment, droplets were formed through the nozzle and the droplet size was measured using a digital camera and image analysis software. As nozzles, commercially available needles with inner diameters (ID) of 0.018 cm and 0.025 cm and self-fabricated nozzles with 3-holes (ID: 0.0135 cm), 4-holes (ID: 0.0135 cm), and 2-holes (ID: 0.0148 cm) were used. The mercury penetration lengths in the nozzles were 1.3 cm for the needles and 0.5 cm for the self-fabricated nozzles. The droplets formed from each nozzle maintained stable spherical shape up to 20 cm below the nozzle. The droplet size measurements were within a 10% error range when compared to the Scheele-Meister model estimates. The experimental results show that the Scheele-Meister model for droplet size estimation can be applied to nozzles that stably form droplets in a water-mercury system.