• Title/Summary/Keyword: 3D network structure

Search Result 326, Processing Time 0.025 seconds

Implementation of A Millimeter-Wave Multiflare-Angle Horn Antenna (밀리미터파 다중개구각 혼안테나 구현)

  • Oh, Kyung-Hyun;Kim, Ji-Hyung;Yang, Seung-Sik;Shin, Sang-Jin;Cho, Young-Ho;Lee, Byung-Ryul;Ahn, Bierng-Chearl
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.29 no.1
    • /
    • pp.36-41
    • /
    • 2018
  • This paper presents an implementation of a millimeter-wave(W band) multiflare-angle horn antenna. The proposed antenna is a multimode dual-polarized square horn having equal E- and H-plane beamwidths and consists of a multimode generating section, a four-square-waveguide exciter, orthomode transducers, and power combiners for the sum pattern formation. The antenna structure has been designed to allow for easy fabrication and the designed antenna has been fabricated to a precision of ${\pm}0.02mm$ by layer-by-layer machining and diffusion bonding. The input reflection coefficient and the radiation pattern of the fabricated antenna have been measured using a network analyzer and a far-field test facility. Measurements show that the proposed antenna has 17.7~18.3 dBi gain, $25.2{\sim}28.5^{\circ}$ beamwidth, and an input VSWR between 1.02~1.75, within ${\pm}0.5GHz$ from the center frequency.

Characterization of FeCo Magnetic Metal Hollow Fiber/EPDM Composites for Electromagnetic Interference Shielding (FeCo 자성 금속 중공형 섬유 고분자 복합재의 전자파 차폐 특성 연구)

  • Choi, Jae Ryung;Jung, Byung Mun;Choi, U Hyeok;Cho, Seung Chan;Park, Ka Hyun;Kim, Won-jung;Lee, Sang-Kwan;Lee, Sang Bok
    • Composites Research
    • /
    • v.28 no.6
    • /
    • pp.333-339
    • /
    • 2015
  • Electromagnetic interference shielding composite with low density ($1.18g/cm^3$) was fabricated using electroless plated FeCo magnetic metal hollow fibers and ethylene propylene diene monomer (EPDM) polymer. Aspect ratio of the fibers were controlled and their hollow structure was obtained by heat treatment process. The FeCo hollow fibers were then mixed with EPDM to manufacture the composite. The higher aspect ratio of the magnetic metal hollow fibers resulted in high electromagnetic interference shielding effectiveness (30 dB) of the composite due to its low sheet resistance (30 ohm/sq). The enhanced electromagnetic interference shielding effectiveness was mainly attributed to the formation of conducting network over the percolation threshold by high aspect ratio of fibers as well as an increase of the reflection loss by impedance mismatch owing to low sheet resistance, absorption loss, and multiple internal reflections loss.

Comparison of Prediction Accuracy Between Classification and Convolution Algorithm in Fault Diagnosis of Rotatory Machines at Varying Speed (회전수가 변하는 기기의 고장진단에 있어서 특성 기반 분류와 합성곱 기반 알고리즘의 예측 정확도 비교)

  • Moon, Ki-Yeong;Kim, Hyung-Jin;Hwang, Se-Yun;Lee, Jang Hyun
    • Journal of Navigation and Port Research
    • /
    • v.46 no.3
    • /
    • pp.280-288
    • /
    • 2022
  • This study examined the diagnostics of abnormalities and faults of equipment, whose rotational speed changes even during regular operation. The purpose of this study was to suggest a procedure that can properly apply machine learning to the time series data, comprising non-stationary characteristics as the rotational speed changes. Anomaly and fault diagnosis was performed using machine learning: k-Nearest Neighbor (k-NN), Support Vector Machine (SVM), and Random Forest. To compare the diagnostic accuracy, an autoencoder was used for anomaly detection and a convolution based Conv1D was additionally used for fault diagnosis. Feature vectors comprising statistical and frequency attributes were extracted, and normalization & dimensional reduction were applied to the extracted feature vectors. Changes in the diagnostic accuracy of machine learning according to feature selection, normalization, and dimensional reduction are explained. The hyperparameter optimization process and the layered structure are also described for each algorithm. Finally, results show that machine learning can accurately diagnose the failure of a variable-rotation machine under the appropriate feature treatment, although the convolution algorithms have been widely applied to the considered problem.

An Intelligent Decision Support System for Selecting Promising Technologies for R&D based on Time-series Patent Analysis (R&D 기술 선정을 위한 시계열 특허 분석 기반 지능형 의사결정지원시스템)

  • Lee, Choongseok;Lee, Suk Joo;Choi, Byounggu
    • Journal of Intelligence and Information Systems
    • /
    • v.18 no.3
    • /
    • pp.79-96
    • /
    • 2012
  • As the pace of competition dramatically accelerates and the complexity of change grows, a variety of research have been conducted to improve firms' short-term performance and to enhance firms' long-term survival. In particular, researchers and practitioners have paid their attention to identify promising technologies that lead competitive advantage to a firm. Discovery of promising technology depends on how a firm evaluates the value of technologies, thus many evaluating methods have been proposed. Experts' opinion based approaches have been widely accepted to predict the value of technologies. Whereas this approach provides in-depth analysis and ensures validity of analysis results, it is usually cost-and time-ineffective and is limited to qualitative evaluation. Considerable studies attempt to forecast the value of technology by using patent information to overcome the limitation of experts' opinion based approach. Patent based technology evaluation has served as a valuable assessment approach of the technological forecasting because it contains a full and practical description of technology with uniform structure. Furthermore, it provides information that is not divulged in any other sources. Although patent information based approach has contributed to our understanding of prediction of promising technologies, it has some limitations because prediction has been made based on the past patent information, and the interpretations of patent analyses are not consistent. In order to fill this gap, this study proposes a technology forecasting methodology by integrating patent information approach and artificial intelligence method. The methodology consists of three modules : evaluation of technologies promising, implementation of technologies value prediction model, and recommendation of promising technologies. In the first module, technologies promising is evaluated from three different and complementary dimensions; impact, fusion, and diffusion perspectives. The impact of technologies refers to their influence on future technologies development and improvement, and is also clearly associated with their monetary value. The fusion of technologies denotes the extent to which a technology fuses different technologies, and represents the breadth of search underlying the technology. The fusion of technologies can be calculated based on technology or patent, thus this study measures two types of fusion index; fusion index per technology and fusion index per patent. Finally, the diffusion of technologies denotes their degree of applicability across scientific and technological fields. In the same vein, diffusion index per technology and diffusion index per patent are considered respectively. In the second module, technologies value prediction model is implemented using artificial intelligence method. This studies use the values of five indexes (i.e., impact index, fusion index per technology, fusion index per patent, diffusion index per technology and diffusion index per patent) at different time (e.g., t-n, t-n-1, t-n-2, ${\cdots}$) as input variables. The out variables are values of five indexes at time t, which is used for learning. The learning method adopted in this study is backpropagation algorithm. In the third module, this study recommends final promising technologies based on analytic hierarchy process. AHP provides relative importance of each index, leading to final promising index for technology. Applicability of the proposed methodology is tested by using U.S. patents in international patent class G06F (i.e., electronic digital data processing) from 2000 to 2008. The results show that mean absolute error value for prediction produced by the proposed methodology is lower than the value produced by multiple regression analysis in cases of fusion indexes. However, mean absolute error value of the proposed methodology is slightly higher than the value of multiple regression analysis. These unexpected results may be explained, in part, by small number of patents. Since this study only uses patent data in class G06F, number of sample patent data is relatively small, leading to incomplete learning to satisfy complex artificial intelligence structure. In addition, fusion index per technology and impact index are found to be important criteria to predict promising technology. This study attempts to extend the existing knowledge by proposing a new methodology for prediction technology value by integrating patent information analysis and artificial intelligence network. It helps managers who want to technology develop planning and policy maker who want to implement technology policy by providing quantitative prediction methodology. In addition, this study could help other researchers by proving a deeper understanding of the complex technological forecasting field.

Effect of 3-Amino-1,2,4-triazole on Microstructure and Properties of Maleated HDPE/Maleated EPDM Blend (3-Amino-1,2,4-triazole이 Maleated HDPE/Maleated EPDM 블렌드의 미세구조 및 물성에 미치는 영향)

  • Kim, Tae Hyun;Chang, Young-Wook;Lee, Yong Woo;Kim, Dong Hyun
    • Elastomers and Composites
    • /
    • v.49 no.1
    • /
    • pp.24-30
    • /
    • 2014
  • 3-Amino-1,2,4-triazole (ATA) (2.5 and 5.0 phr) was incorporated into a immiscible maleated ethylene propylene diene rubber(mEPDM)/maleated high density polyethylene(mHDPE) (50 wt%/50 wt%) blend by melt mixing. Effects of the ATA on structure, mechanical and rheological properties of the blend was investigated. FT-IR and DMA results revealed that supramolecular hydrogen bonding interactions between the polymer chains occur by reaction of ATA with maleic anhydride grafted onto the component polymers in the blend, which induces the physical crosslinks in the blend. FE-SEM analysis showed that mEPDM forms a dispersed phase in continuous mHDPE matrix, and the blend with the ATA has finer phase morphology as compared to the blend without the ATA. By the addition of ATA in the blend, there were significant increases in tensile strength, modulus and elongation-at-break as well as elastic recoverability. Melt rheology studies revealed that ATA induced substantial increase in storage modulus and complex viscosity of the blend at the melt state.

Factors Affecting Health Behaviors for Lifestyle-related Diseases of Public Officials Using Health Belief Model (건강믿음모형을 이용한 공무원의 생활습관병에 대한 건강행동 요인)

  • Kang, Jeong-Suk;Cho, Young-Chae
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.11
    • /
    • pp.239-251
    • /
    • 2017
  • This study attempted to identify the health behaviors and related factors of lifestyle related diseases among some public officials. The study subjects were 729 administrative officers of the general public office of the government in D metropolitan city. The data collection was conducted by self-administered questionnaire from February 1 to March 31, 2016. As a result, the health behavior score for lifestyle related diseases showed a significant positive correlation with vulnerability, the effectiveness of health behavior and information obtained from the media about lifestyle-related diseases, while it showed a significant negative correlation with the barriers to health behaviors concerning lifestyle related diseases. As a result of the covariance structure analysis, vulnerability and seriousness about lifestyle related diseases were the most important factors affecting health behavior for lifestyle related diseases. The next most important factors were a family history of lifestyle related diseases, information obtained from the media, effectiveness of and barriers to health behavior, instrumental support, and emotional support. These results suggest that each factor constituting the Health Belief Model (HBM) (perceived vulnerability and seriousness about lifestyle related diseases, perceived effectiveness and barriers to health behaviors, family history of lifestyle related diseases, information obtained from the mass media about lifestyle related diseases, social support network for lifestyle related diseases) is an important factor to consider in practicing health behaviors for lifestyle related diseases. Therefore, it is important to accurately understand the factors related to the practice of the health behaviors of the subjects and to manage them continuously.

Residual Stress Behavior and Characterization of Polyimide Crosslinked Networks via Ring-opening Metathesis Polymerization (개환 복분해 중합을 통한 가교형 폴리이미드 박막의 잔류응력 거동 및 특성 분석)

  • Nam, Ki-Ho;Seo, Jongchul;Jang, Wonbong;Han, Haksoo
    • Polymer(Korea)
    • /
    • v.38 no.6
    • /
    • pp.752-759
    • /
    • 2014
  • Crosslinked polyimides (PIs) were synthesized by reacting 4,4'-(hexafluoroisopropylidene)-diphthalic anhydride (6FDA) and 2,2'-bis(trifluoromethyl)benzidine (TFDB) with various ratios of the cross-linkable, end-capping agent cis-1,2,3,6-tetrahydrophthalic anhydride (CDBA) via ring-opening metathesis polymerization. Residual stress behaviors were investigated in-situ during thermal imidization of the crosslinked PI precursors using a thin film stress analyzer (TFSA) by wafer bending method. The thermal properties were investigated via differential scanning calorimetry (DSC), thermomechanical analysis (TMA), and thermogravimetric analysis (TGA). The optical properties were measured by ultraviolet-visible spectrophotometer (UV-vis) and spectrophotometry. All properties were interpreted with respect to their morphology of crosslinked networks. With increasing the amounts of the end-capping agent, the residual stress decreased from 27.9 to -1.3 MPa, exhibited ultra-low stress and high thermal properties. The minimized residual stress and enhanced thermal properties of the crosslinked PI makes them potential candidates for versatile high-density multi-layer structure applications.

A Control Method for designing Object Interactions in 3D Game (3차원 게임에서 객체들의 상호 작용을 디자인하기 위한 제어 기법)

  • 김기현;김상욱
    • Journal of KIISE:Computing Practices and Letters
    • /
    • v.9 no.3
    • /
    • pp.322-331
    • /
    • 2003
  • As the complexity of a 3D game is increased by various factors of the game scenario, it has a problem for controlling the interrelation of the game objects. Therefore, a game system has a necessity of the coordination of the responses of the game objects. Also, it is necessary to control the behaviors of animations of the game objects in terms of the game scenario. To produce realistic game simulations, a system has to include a structure for designing the interactions among the game objects. This paper presents a method that designs the dynamic control mechanism for the interaction of the game objects in the game scenario. For the method, we suggest a game agent system as a framework that is based on intelligent agents who can make decisions using specific rules. Game agent systems are used in order to manage environment data, to simulate the game objects, to control interactions among game objects, and to support visual authoring interface that ran define a various interrelations of the game objects. These techniques can process the autonomy level of the game objects and the associated collision avoidance method, etc. Also, it is possible to make the coherent decision-making ability of the game objects about a change of the scene. In this paper, the rule-based behavior control was designed to guide the simulation of the game objects. The rules are pre-defined by the user using visual interface for designing their interaction. The Agent State Decision Network, which is composed of the visual elements, is able to pass the information and infers the current state of the game objects. All of such methods can monitor and check a variation of motion state between game objects in real time. Finally, we present a validation of the control method together with a simple case-study example. In this paper, we design and implement the supervised classification systems for high resolution satellite images. The systems support various interfaces and statistical data of training samples so that we can select the most effective training data. In addition, the efficient extension of new classification algorithms and satellite image formats are applied easily through the modularized systems. The classifiers are considered the characteristics of spectral bands from the selected training data. They provide various supervised classification algorithms which include Parallelepiped, Minimum distance, Mahalanobis distance, Maximum likelihood and Fuzzy theory. We used IKONOS images for the input and verified the systems for the classification of high resolution satellite images.

Analysis and cloning of cAMP receptor protein(CRp) gene in Serratia marcescens (Serratia marcescens에서 cAMP receptor protein(CRP) 유전자의 클로닝 해석)

  • Yoo, Ju-soon;Kim, Hae-Sun;Moon, Jong-Hwan;Chung, Soo-Yeol;Choi, Yong-Lark
    • Journal of Life Science
    • /
    • v.8 no.3
    • /
    • pp.263-271
    • /
    • 1998
  • One of the better-characterized transcription factor of E. coli is the cAMP receptor protein(CRP) and the CRP binds cAMP and DNA. The cAMP-CRP complex is involved in regulation of many genes at bacteria. The cAMP-CRP regulatory element represents, in some respects, a global regulatory network. The aim of this work was to study the structure and the mechanisms controlling the expression of CRP in Serratia marcescens. We have been get 5 different clones from Serratia which stimulated the cells to use maltose as a sole carbon source in E. coli TP2139. The crp gene clone, pCKB12, was confirmed by Southern hybridization with E. coli crp gene. The location of the crp gene was determined by construction subclones carrying various portions of pCKB12. To investigate the potential role of CRP in E. coli, lacZ fused plasmids were constructed and investigated the ${\beta}$-galactosidase activity of the fused plasmid. The Serratiamarcescens cAMP receptor protein can substitute the E. coli CRP in transcriptional activation at the lacZ gene. These results suggest that Serratia marcescens cAMP receptor protein complex functions to regulate several promoters in E. coli.

  • PDF

Exploratory Study of Applying Historiography and SPLC for Developing Information Services: A Case Study of LED Domain (연구지원 정보서비스를 위한 히스토리오그래프와 SPLC 활용에 관한 실험적 연구: LED 분야 사례를 중심으로)

  • Yu, So-Young
    • Journal of the Korean Society for information Management
    • /
    • v.30 no.3
    • /
    • pp.273-296
    • /
    • 2013
  • The purpose of this study is to examine the data coverage and citation threshold for analyzing SPLC(Search Path Link Count) as a main path of a historiograph of a certain topic in order to provide 'core' papers of global research trends to a researcher affiliated with a local R&D institution. 5 datasets were constructed by retrieving and collecting 2,318 articles on RGB LED on Web of Science published from 1990-2013 and 20,109 articles which cited these original 2,318. The SPLC analysis was performed on each dataset by increasing the threshold of citation counts, and the changes and resilience of the 28 extraced networks were compared. The results of user feedback on 198 unique core papers from 28 SPLC networks received from LED researchers affiliated with a Korean government-sponsored research institution were also analyzed. As a result, it is found that the nodes in each SPLC network in each dataset were differentiated by the citation counts, while the changes in the structure of SPLC networks were slight after the networks' citation counts were set at 40. Additionally, the user feedback showed that personalized research interest generally matched to the global research trends identified by the SPLC analysis.