• Title/Summary/Keyword: new hybrid

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Development of New Rapid Prototyping System Performing both Deposition and Machining (II) (적층과 절삭을 복합적으로 수행하는 새로운 개념의 판재 적층식 쾌속 시작 시스템의 개발(II) - 공정계획 시스템 -)

  • Heo, Jeong-Hun;Lee, Geon-U
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.9 s.180
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    • pp.2235-2245
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    • 2000
  • The necessity of using rapid prototyping(RP) for short-run manufacturing is continuously driving a development of a cost-effective technique that will produce completely-finished quality parts in a very short time. To meet these demands, the improvements in production speed, accuracy, materials, aid cost are crucial. Thus, a new hybrid-RP system performing both deposition and machining in a station is proposed. For the new hybrid RP process to maintain the same degree of process automation as in currently available processes like SLA or FDNI, a sophisticated process planning system is developed. In the process planner, CAD models(STEP AP203) are partitioned into 3D manufacturable volumes called 'Ueposition feature segment"(DFS) after machining features called "machining feature segmenf'(MFS) are extracted from the initial CAD model. Once MFS and DFS are identified, the process planner arranges them into a chain of processes and automatically generates machining information for each DFS and MFS. The goal of this paper is to present a framework for a process planning system for hybrid RP processes and to outline the geometric algorithms involved in developing such an environment.

New hybrid stochastic-deterministic rock block analysis method in tunnels (터널의 신 하이브리드 추계학적-확정론적 암반블럭 해석기법)

  • Hwang, Jae-Yun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.12 no.3
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    • pp.265-274
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    • 2010
  • In many tunnels, falling or sliding of rock blocks often occur, which cannot be predicted because of the complexity of rock discontinuities and it has brought an exponential increase in costs and time to manage. It is difficult to estimate the properties of rock masses before the tunnel excavation. The observational design and construction method in tunnels has been becoming important recently. In this study, a new hybrid stochastic-deterministic rock block analysis method for the prediction of the unstable rock blocks before the tunnel excavation is proposed, and then applied to the tunnel construction based on actual rock discontinuity information observed in the field. The comparisons and investigations with the analytical results in the tunnel construction have confirmed the validity and applicability of this new hybrid stochastic-deterministic rock block analysis method in tunnels.

A New Item Recommendation Procedure Using Preference Boundary

  • Kim, Hyea-Kyeong;Jang, Moon-Kyoung;Kim, Jae-Kyeong;Cho, Yoon-Ho
    • Asia pacific journal of information systems
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    • v.20 no.1
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    • pp.81-99
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    • 2010
  • Lately, in consumers' markets the number of new items is rapidly increasing at an overwhelming rate while consumers have limited access to information about those new products in making a sensible, well-informed purchase. Therefore, item providers and customers need a system which recommends right items to right customers. Also, whenever new items are released, for instance, the recommender system specializing in new items can help item providers locate and identify potential customers. Currently, new items are being added to an existing system without being specially noted to consumers, making it difficult for consumers to identify and evaluate new products introduced in the markets. Most of previous approaches for recommender systems have to rely on the usage history of customers. For new items, this content-based (CB) approach is simply not available for the system to recommend those new items to potential consumers. Although collaborative filtering (CF) approach is not directly applicable to solve the new item problem, it would be a good idea to use the basic principle of CF which identifies similar customers, i,e. neighbors, and recommend items to those customers who have liked the similar items in the past. This research aims to suggest a hybrid recommendation procedure based on the preference boundary of target customer. We suggest the hybrid recommendation procedure using the preference boundary in the feature space for recommending new items only. The basic principle is that if a new item belongs within the preference boundary of a target customer, then it is evaluated to be preferred by the customer. Customers' preferences and characteristics of items including new items are represented in a feature space, and the scope or boundary of the target customer's preference is extended to those of neighbors'. The new item recommendation procedure consists of three steps. The first step is analyzing the profile of items, which are represented as k-dimensional feature values. The second step is to determine the representative point of the target customer's preference boundary, the centroid, based on a personal information set. To determine the centroid of preference boundary of a target customer, three algorithms are developed in this research: one is using the centroid of a target customer only (TC), the other is using centroid of a (dummy) big target customer that is composed of a target customer and his/her neighbors (BC), and another is using centroids of a target customer and his/her neighbors (NC). The third step is to determine the range of the preference boundary, the radius. The suggested algorithm Is using the average distance (AD) between the centroid and all purchased items. We test whether the CF-based approach to determine the centroid of the preference boundary improves the recommendation quality or not. For this purpose, we develop two hybrid algorithms, BC and NC, which use neighbors when deciding centroid of the preference boundary. To test the validity of hybrid algorithms, BC and NC, we developed CB-algorithm, TC, which uses target customers only. We measured effectiveness scores of suggested algorithms and compared them through a series of experiments with a set of real mobile image transaction data. We spilt the period between 1st June 2004 and 31st July and the period between 1st August and 31st August 2004 as a training set and a test set, respectively. The training set Is used to make the preference boundary, and the test set is used to evaluate the performance of the suggested hybrid recommendation procedure. The main aim of this research Is to compare the hybrid recommendation algorithm with the CB algorithm. To evaluate the performance of each algorithm, we compare the purchased new item list in test period with the recommended item list which is recommended by suggested algorithms. So we employ the evaluation metric to hit the ratio for evaluating our algorithms. The hit ratio is defined as the ratio of the hit set size to the recommended set size. The hit set size means the number of success of recommendations in our experiment, and the test set size means the number of purchased items during the test period. Experimental test result shows the hit ratio of BC and NC is bigger than that of TC. This means using neighbors Is more effective to recommend new items. That is hybrid algorithm using CF is more effective when recommending to consumers new items than the algorithm using only CB. The reason of the smaller hit ratio of BC than that of NC is that BC is defined as a dummy or virtual customer who purchased all items of target customers' and neighbors'. That is centroid of BC often shifts from that of TC, so it tends to reflect skewed characters of target customer. So the recommendation algorithm using NC shows the best hit ratio, because NC has sufficient information about target customers and their neighbors without damaging the information about the target customers.

Intermixing Surface and Volume Visualization Using Layered Depth Images (다중 깊이 영상을 이용한 볼륨-표면 혼합 가시화)

  • Kye, Heewon
    • Journal of Korea Game Society
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    • v.13 no.2
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    • pp.99-110
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    • 2013
  • As volume rendering has been applied for computer game, the visualization of volume data with surface data in one scene has been required. Though a hybrid rendering of volume and surface data have been developed using the GPGPU functionality, computer games which run on low-level hardware are difficult to perform the hybrid rendering. In this paper, we propose a new hybrid rendering based on DirectX 9.0 and general hardware. We generate the layered depth images from surface data using a new method to reduce the depth complexity and generation time. Then, we perform the hybrid rendering using the layered depth images. In the rendering process, we suggest a new method to transform the coordinate system from a surface coordinate to a volume coorinate and propose an accelerated rendering technique. As the result, we can perform volume-surface hybrid rendering in an efficient way.

HYBRID POWER FLOW ANALYSIS USING SEA PARAMETERS

  • Park, Y.H.;Hong, S.Y.
    • International Journal of Automotive Technology
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    • v.7 no.4
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    • pp.423-439
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    • 2006
  • This paper proposes a hybrid analytic method for the prediction of vibrational and acoustic responses of reverberant system in the medium-to-high frequency ranges by using the PFA(Power Flow Analysis) algorithm and SEA(Statistical Energy Analysis) coupling concepts. The main part of this method is the application of the coupling loss factor(CLF) of SEA to the boundary condition of PFA in reverberant system. The hybrid method developed shows much more promising results than the conventional SEA and equivalent results to the classical PFA for various damping loss factors in a wide range of frequencies. Additionally, this paper presents applied results of hybrid power flow finite element method(hybrid PFFEM) by formulating the new joint element matrix with CLF to analyze the vibrational responses of built-up structures. Finally, the analytic results of coupled plate structures and an automobile-shaped structure using hybrid PFFEM were predicted successively.

Application of the Photoelastic Experimental Hybrid Method with New Numerical Method to the High Stress Distribution (고응력 분포에 새로운 광탄성실험 하이브릿법 적용)

  • Hawong, Jai-Sug;Tche, Konstantin;Lee, Dong-Hun;Lee, Dong-Ha
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.73-78
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    • 2004
  • In this research, the photoelastic experimental hybrid method with Hook-Jeeves numerical method has been developed: This method is more precise and stable than the photoelastic experimental hybrid method with Newton-Rapson numerical method with Gaussian elimination method. Using the photoelastic experimental hybrid method with Hook-Jeeves numerical method, we can separate stress components from isochromatics only and stress intensity factors and stress concentration factors can be determined. The photoelastic experimental hybrid method with Hook-Jeeves had better be used in the full field experiment than the photoelastic experimental hybrid method with Newton-Rapson with Gaussian elimination method.

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A Study on the Design and the Analysis of Hybrid Inverter (하이브리드 인버터 설계 및 특성해석에 관한 연구)

  • 오진석;김윤식;노창주
    • Journal of Advanced Marine Engineering and Technology
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    • v.19 no.3
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    • pp.99-106
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    • 1995
  • PWM(Pluse Width Modulation) induction motor drives are being used in greater numvers through a wide variety of industrial and commercial applications. In this paper, a new speed control algorithm (hybrid algorithm) for induction motor drives that uses regular sampled PWM and harmonic elimination PWM is presented. The hybrid algorithm in implemeted on the computer to obtain solutions from the calculation equations of the width of the pulses and the firing angles for the selected harmonic elimination. this paper describes the time delay effects and the suitable compensating methods moreover, optical transmission system for driving signals is proposed and is compared with general trnasmission system. The hybrid inverter was tested with induction motor, and these test results are shown that this hybrid inverter closely approximates and exhibits many of the desirable performance characteristic distortions and eliminated the objectionable harmonics. Finally, detailed experimental investigation of the proposed hybrid scheme in presented.

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A Study on the Effect of Complementary Bundling Based on the Categorization of the New Hybrid IT Product (하이브리드 IT신제품의 범주화에 따른 보완재 번들링의 효과성에 관한 연구)

  • Park, Yoonseo;Kim, Yongsik
    • Journal of Information Technology Services
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    • v.13 no.4
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    • pp.19-43
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    • 2014
  • Categorization means the process labeling or identifying an object based on what people already know or its similarity for people to be easily perceptible in external environment. If it is categorized, it is schematically conjectured from typical characteristic of the category. In this sense, the categorization of new products has an important effect upon the market performance. Nevertheless, the categorization of innovative new products is not easy and occasionally very ambiguous. In this study, we discuss how to strengthen the categorization strategy of new hybrid IT products through complementary bundling. The model of this study is based on Technology Acceptance Model (TAM) with resistance variable and verifies the statistical significance by undertaking a survey on consumers' awareness. In addition, we review the moderating effects of prior knowledge in the adoption process of complementary bundling. Through this analysis, we find out the structural relationship among the factors affecting adoption of complementary bundling. Also, it show that the influence of prior knowledge in respect of the adoption process is greater than others in case that there exists significant heterogeneity among strategic categories and complements. In conclusion, these findings suggest the following managerial implication. The categorization strategy of new hybrid IT product can be enhanced by complementary bundling, but the suitability among strategic category and complements should be evaluated exhaustively.

Development of New Rapid Prototyping System Performing both Deposition and Machining(I);Process and Framework (적층과 절삭을 복합적으로 수행하는 새로운 개녕의 판재 적층식 쾌속 시작 시스템의 개발(I);공정 및 기반구조)

  • Heo, Jeong-Hun;Hwang, Jae-Cheol;Lee, Geon-U;Kim, Jong-Won;Han, Dong-Cheol;Ju, Jong-Nam;Park, Jong-U
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.8 s.179
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    • pp.1958-1967
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    • 2000
  • Rapid Prototyping( RP ) has been increasingly applied in the process of design and development of new products. RP can shrink the time and expense required to bring a new product from initial concept to production. However, the necessity of using RP for short-run manufacturing is continuously driving a development of a cost-effective technique that will produce completely-finished quality parts in a very short time. To meet these demands, the improvements in production speed, accuracy materials, and cost are crucial. Thus, a new hybrid-RP system performing both deposition and machining in a station is proposed in this paper. It incorporates both material deposition in layers and material removal from the outer surface of the layer to produce the required surface finish. The new hybrid-RP system can dramatically reduce the total build time and fabricate largo-sized and freeform objects because it uses very thick layers, i.e.

A Making of Aesthetic Dental restorations with Nano Hybrid Ceramic material by CAD/CAM System (치과 CAD/CAM용 Nano Hybrid Ceranic 소재를 이용한 심미 치과보철물의 제작)

  • Choi, Beom-jin
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.25 no.2
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    • pp.98-108
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    • 2016
  • In recent days, perhaps the biggest driver in new material development is the desire to improve restorations esthetics compared to the traditional metal substructure based ceramics or all-ceramic restorations. Each material type performs differently regarding strength, toughness, effectiveness of machining and the final preparation of the material prior to placement. For example, glass ceramics are typically weaker materials which limits its use to single-unit restorations. On the other hand, zirconia has a high fracture toughness which enables multi-unit restorations. This material requires a long time sintering procedure which excludes its use for fast chair side production. Hybrid ceramic material developed for CAD/CAM system is contained improved nano ceramic elements. This new material, called a Resin Nano Hybrid Ceramic is unique in durability of function and aesthetic base compositions. The new nano-hybrid ceramic material is not a composite resin. It is also not a pure ceramic. The material is a mixture of both and consists of nano-ceramic fillers. Like a composite, the material is not brittle and is fracture resistant. Like a glass ceramic, the material has excellent polish retention for lasting esthetics. The material is easily machined by chair side or in a dental lab side, could be an useful restorative option.