• Coupled systems mechanics
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• 제12권1호
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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.

• Journal of Information Processing Systems
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• 제19권1호
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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.

• International Journal of Computer Science & Network Security
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• 제24권8호
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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.

• 대한산업공학회지
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• 제33권4호
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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.

• 한국CDE학회논문집
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• 제5권1호
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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.

• 대한산업공학회지
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• 제43권1호
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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.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2004년도 추계학술대회 및 정기총회
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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.

• 한국항공우주학회지
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• 제39권12호
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• pp.1087-1096
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• 2011

본 연구의 목적은 오픈 소스 코드에서 제공하는 해석자의 알고리즘을 수정하여 로터의 유동 해석에 적합하도록 해석자를 확장하고, 이를 검증하는 것이다. 우선 로터의 추력에 의해 발생하는 후류에 의한 유동 흐름의 해석이 가능하도록 오픈 소스 코드인 OpenFOAM의 표준 해석자의 알고리즘을 개선하였다. 또한, 로터의 추력 예측을 위해서 깃요소 이론을 기반으로 한 가상 블레이드 기법을 적용하였다. 깃요소 이론에서의 유효받음각을 구하기 위한 로터 디스크 상의 속도 성분은 해석자 내에서 반복계산시마다 수렴되는 속도를 사용하였다. 개발된 로터 해석자를 사용하여 로터 유입류 해석을 수행하고 그 결과를 실험 결과 및 타 수치해석 코드의 결과와 비교하여 신뢰도를 검증하였다. 로터-동체 상호작용 해석을 통해 헬리콥터 시스템 전체에 대한 로터 해석자의 적용가능성을 확인하였다.

• 한국통신학회논문지
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• 제38C권7호
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• pp.587-594
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• 2013

웹 2.0의 발전과 스마트 디바이스의 보급은 제한적인 정보와 평면적인 서비스에 맞춤화된 기존의 웹서비스를 탈피하여 사용자가 원하는 다차원적인 정보와 다양한 서비스가 융합된 형태의 매쉬업 서비스를 탄생시키는 요인이 되었다. 매쉬업 서비스는 다양한 웹서비스가 융합된 서비스를 지칭하며 웹서비스의 인터페이스인 Open API를 통해 보다 손쉽게 지원되고 있다. 하지만 현재의 매쉬업 서비스는 개발자 중심의 서비스 제공 방식으로 인해 개인 맞춤화된 서비스를 제공 받고자 하는 다양한 사용자의 욕구를 충족시키지 못하는 문제점이 있다. 이러한 문제점 해결을 위해 매쉬업을 손쉽게 하는 매쉬업 프레임워크에 대한 연구가 다양하게 이루어지고 있지만 아직 그 수준이 미비하다. 본 논문에서는 동적으로 웹서비스를 합성하여 매쉬업 서비스를 제공하는 매쉬업 프레임워크의 요소기술로써 Open API 자동 합성을 위한 Open API 선별 기법 및 합성 방안에 대해 소개 하였다.

• 한국정보통신학회논문지
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• 제18권11호
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• pp.2593-2599
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• 2014

최근 모바일 앱에서도 오픈소스 소프트웨어를 이용한 개발이 활발하게 이루어지고 있다. 오픈소스 모바일 컴포넌트의 경우 사용자 인터페이스 구현을 위한 컴포넌트의 재사용성이 용이하다는 이유로 기능적 역할의 컴포넌트보다 더욱 많이 사용되는 경향이 있다. 이런 특징으로 인해 기존의 오픈소스 소프트웨어 선정절차나 상용 컴포넌트 선정절차 두 가지 연구 모두 오픈소스 모바일 컴포넌트 선정에 그대로 적용하기에는 무리가 있다. 본 논문에서는 기존에 연구된 오픈소스 소프트웨어 선정절차를 모바일 컴포넌트 선정에 적합하도록 수정, 보완하였다. 본 연구는 모바일 앱을 개발할 경우, 요구되는 기능을 충족하는 오픈소스 컴포넌트를 쉽게 검색하고 선정할 수 있는 효율적인 절차를 제시함으로써 모바일 앱 개발의 생산성을 높여줄 수 있다.