• Title/Summary/Keyword: open problem

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Clinical application of maxillary tissue bone-borne expander and biocreative reverse curve system in the orthodontic retreatment of severe anterior open bite with transverse discrepancy: A case report

  • Choi, Jin-Young;Jin, Bai;Kim, Seong-Hun
    • The korean journal of orthodontics
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    • v.52 no.5
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    • pp.372-382
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    • 2022
  • Anterior open bite and transverse discrepancy are often accompanied by hyperdivergent skeletal patterns. In addition, degenerative joint disorders and vertical maxillary excess contribute to an unfavorable convex facial profile with a retruded chin. Correction of this complex three-dimensional problem with orthodontic treatment alone is considered challenging owing to anatomical limitations. Moreover, a history of orthodontic treatment with premolar extraction makes retreatment difficult. This case report illustrates the application of a maxillary tissue bone-borne expander and biocreative reverse curve system in a 23-year-old female patient with a severe anterior open bite and transverse discrepancy who underwent orthodontic treatment with four premolar extractions. By setting the treatment target under precise diagnosis and using appropriate appliances, a satisfactory treatment result could be achieved without orthognathic surgery.

The plate on the nonlinear dynamic foundation under moving load

  • Phuoc T. Nguyen;Thieu V. Vi;Tuan T. Nguyen;Van T. Vu
    • Coupled systems mechanics
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    • v.12 no.1
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    • pp.83-102
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    • 2023
  • First introduced in 2016, the dynamic foundation model is an interesting topic in which the foundation is described close to reality by taking into account the influence of the foundation mass in the calculation of oscillation and is an important parameter that should be considered. In this paper, a follow-up investigation is conducted with the object of the Mindlin plate on a nonlinear dynamic foundation under moving loads. The base model includes nonlinear elastic springs, linear Pasternak parameters, viscous damping, and foundation mass. The problem is formulated by the finite element analysis and solved by the Newmark-β method. The displacement results at the center of the plate are analyzed and discussed with the change of various parameters including the nonlinear stiffness, the foundation mass, and the load velocity. The dynamic response of the plate sufficiently depends on the foundation mass.

Development of Automatic Conversion System for Pipo Painting Image Based on Artificial Intelligence

  • Minku, Koo;Jiyong, Park;Hyunmoo, Lee;Giseop, Noh
    • Journal of Information Processing Systems
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    • v.19 no.1
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    • pp.33-45
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    • 2023
  • This paper proposes an algorithm that automatically converts images into Pipo, painting images using OpenCV-based image processing technology. The existing "purity," "palm," "puzzling," and "painting," or Pipo, painting image production method relies on manual work, so customized production has the disadvantage of coming with a high price and a long production period. To resolve this problem, using the OpenCV library, we developed a technique that automatically converts an image into a Pipo painting image by designing a module that changes an image, like a picture; draws a line based on a sector boundary; and writes sector numbers inside the line. Through this, it is expected that the production cost of customized Pipo painting images will be lowered and that the production period will be shortened.

Open Research Problem for effective IoT Authentication

  • Mihir Mehta;Kajal Patel
    • International Journal of Computer Science & Network Security
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    • v.24 no.8
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    • pp.174-178
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    • 2024
  • IoT is collection of different "things" which are associated with open web. As all the things are connected to the Internet, it offers convenience to end users for accessing the resources from "Any Where, Any Time" throughout the globe. At the same time, open nature of IoT provides a fertile ground to an intruder for launching different security related threats. If we can no apply proper security safeguards to the IoT System, then it will be not useful to society. Authentication, Encryption, Trust Management and Secure Routing are different domains to offer security in IoT system. Among them, Authentication is very much important security service as it validates device identity before granting access to system services/ resources. Existing IoT Authentication algorithms are fail to verify device identity in unambiguous way. They are vulnerable to different security threats such as Key Stolen threat, MITM threat and Location Spoofing threat. So, it is a demand of time to design an efficient and secure Multi-factor IoT algorithm which can offer better security and validate device identity in unambiguous way.

The Multi-period Demand Changing Location Problem (기간별 수요가 변하는 상황에서의 입지선정 문제에 관한 연구)

  • Choi, Soon-Sik;Lee, Young-Hoon
    • Journal of Korean Institute of Industrial Engineers
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    • v.33 no.4
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    • pp.439-446
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    • 2007
  • A new location model, where the demand varies by periods, and the facility at each period can be open or closed depending on the demand, is discussed in this paper. General facility location problem is extended with the assumption that demands per period vary. A mixed integer programming is suggested and the solution is found for various instances which are randomly generated. Instances included various cases with respect to the length of periods, moving distance of customer locations, and cost structure. The characteristics of optimal solutions are analyzed for various cases, and it is shown that demand changing location model can be applied in a practical fields of supply chains.

Product Development in the Network-Centric Engineering Environment: Concept and Approach (네트워크 기반 엔지니어링 환경에서의 제품 개발: 개넘과 접근방식)

  • 방건동
    • Korean Journal of Computational Design and Engineering
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    • v.5 no.1
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    • pp.79-87
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    • 2000
  • This paper presents an integrated but open product development environment for distributed and collaborative design. The web-based framework, called DOME, allows designers to build integrated models using both local and distributed resources, and to collaborate by exchanging services in a network-centric product development environment. Thus, an integrated model can be created while each participant focuses on his or her own area of expertise. A design problem model is created by connecting modules, which represent specific system components, analysis capabilities/software, disciplines, or organizations relevant to the problem. The modules interact with each other using service exchanges based upon the CORBA standard communication protocol. The goal of this framework is tall provide the ability to rapidly construct integrated design problem models to facilitate collaborative design work, improve product quality and reduce development time. Ultimately, it should allow specialized engineering applications and design problem models to operate under a common design environment.

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Dynamic Decisions using Variable Neighborhood Search for Stochastic Resource-Constrained Project Scheduling Problem (확률적 자원제약 스케줄링 문제 해결을 위한 가변 이웃탐색 기반 동적 의사결정)

  • Yim, Dong Soon
    • Journal of Korean Institute of Industrial Engineers
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    • v.43 no.1
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    • pp.1-11
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    • 2017
  • Stochastic resource-constrained project scheduling problem is an extension of resource-constrained project scheduling problem such that activity duration has stochastic nature. In real situation where activity duration is not known until the activity is finished, open-loop based static policies such as activity-based policy and priority-based policy will not well cope with duration variability. Then, a dynamic policy based on closed-loop decision making will be regarded as an alternative toward achievement of minimal makespan. In this study, a dynamic policy designed to select activities to start at each decision time point is illustrated. The performance of static and dynamic policies based on variable neighborhood search is evaluated under the discrete-event simulation environment. Experiments with J120 sets in PSPLIB and several probability distributions of activity duration show that the dynamic policy is superior to static policies. Even when the variability is high, the dynamic policy provides stable and good solutions.

Structural results and a solution for the product rate variation problem : A graph-theoretic approach

  • Choe Sang-Woong
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.10a
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    • pp.250-278
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    • 2004
  • The product rate variation problem, to be called the PRVP, is to sequence different type units that minimizes the maximum value of a deviation function between ideal and actual rates. The PRVP is an important scheduling problem that arises on mixed-model assembly lines. A surge of research has examined very interesting methods for the PRVP. We believe, however, that several issues are still open with respect to this problem. In this study, we consider convex bipartite graphs, perfect matchings, permanents and balanced sequences. The ultimate objective of this study is to show that we can provide a more efficient and in-depth procedure with a graph theoretic approach in order to solve the PRVP. To achieve this goal, we propose formal alternative proofs for some of the results stated in the previous studies, and establish several new results.

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The Extension and Validation of OpenFOAM Algorithm for Rotor Inflow Analysis using Actuator Disk Model (Actuator Disk 모델 기반의 로터 유입류 해석을 위한 OpenFOAM 알고리즘 확장)

  • Kim, Tae-Woo;Oh, Se-Jong;Yee, Kwan-Jung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.12
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    • pp.1087-1096
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    • 2011
  • The purpose of current study is to develop and verify the newly developed solver for analyzing rotor flow using the open-source code. The algorithm of standard solver, OpenFOAM, is improved to analyze the rotor inflow with and without fuselage. For the calculation of the rotor thrust, the virtual blade method based on the blade element method is employed. The inflow velocities on the rotor disk used to specify the effective angle of attack, have been included in the solver. The results of the current rotor inflow analysis are verified by comparing with other experimental and numerical results. It was confirmed that the modified solver provides satisfactory results for rotor-fuselage interaction problem.

API Selection and Automatic Open API Composition Method Based on REST Protocol (REST 프로토콜 기반의 API 선별 기법 및 Open API 자동 합성 방안)

  • Kim, Sang-Il;Kim, Hwa-Sung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.7
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    • pp.587-594
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    • 2013
  • With the development of web 2.0 and the rapid diffusion of smart devices, current web service, which only provides very limited information and service, has been transformed into user-friendly and comprehensive web service called mash-up service. Mash-up service is defined as comprehensive service that is created by combining variety of web services. When composing a mesh-up service, Open API is used as web service interface. Current mash-up service, however, has fundamental problem in that it could not satisfy the various needs of users who want I-centric personalized service because it is developed and provided by service developers. To overcome these obstacles, a lot of studies on mesh-up framework are being performed for improving mash-up proess though, it is still in beginning stage. In this paper, we introduce an API selection and compostion method as the key technology for mesh-up framework that support the automatic creation of mesh-up service.