• Earthquakes and Structures
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• 제2권3호
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• pp.297-321
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• 2011

The seismic design of a two-storey precast reinforced-concrete building structure equipped with viscous dampers is presented in this paper with twofold purpose. The first goal is to verify the applicability of a practical procedure for the identification of the mechanical characteristics of the viscous dampers which allow to achieve target performance levels, originally proposed by the authors for moment-resisting building frames, also with reference to "pendular" structures. The second goal is to investigate the effectiveness of the use of viscous dampers (as compared with traditional lateral-resisting stiff braces) for the seismic design of precast not moment-resisting concrete structures.

• 한국정보시스템학회지:정보시스템연구
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• 제30권2호
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• pp.127-146
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• 2021

Research Purpose Advances in digital technology have facilitated the widespread adoption of online learning, which has become a substantial way of learning. Although digital immigrants have become a main group of users of learning online, there is a lack of understanding of their online learning. This study aims to explore digital immigrants' adoption of online learning from the goal-pursuit perspective to gain insight into how they use online learning. Research Method A laddering interview was conducted with 22 Korean adults to elicit their goals in online learning. Then, a means-end chain analysis was used to derive their hierarchical goal structure. Findings The results reveal digital immigrants' goal structure of online learning, consisting of four attributes of online learning (e.g., accessibility, diversity, up-to-dateness, and repeatability) and six goals (e.g., self-esteem, enjoyment, recognition, productivity, gaining insights, and positive relations). This study contributes to the literature by providing a rich picture of their use of online learning.

• 대한수학회보
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• 제38권3호
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• pp.551-564
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• 2001

We view Weyl structures as generalizations of Riemannian metrics and study the critical points of geometric functional which involve scalar curvature, defined on the space of Weyl structures on a closed 4-manifold. The main goal here is to provide a framework to analyze critical Weyl structures by defining functionals, discussing function spaces and writing down basic formulas for the equations of critical points.

• 에너지공학
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• 제21권3호
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• pp.272-279
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• 2012

정부의 온실가스 감축목표에 따라 건축물 부분은 26.9%가 할당 되었다. 신규 및 기존 주택에 대해 저에너지 지속 가능한 건축물의 변화는 과제이자 필수 불가결한 문제로 대두 되었다. 신축 건축물은 각종 제도와 규제완화로 저탄소 지속가능한 에너지 변환을 유도하고 있으나 기존건축물 670만동에 대해서는 전체 감축 목표는 나와 있는데 감축방안에 대한 기준이나 방향 제시가 부족한 것이 현실이다. 본 연구는 선정 대상 건축물을 직접 방문하여 현황을 조사하고 적용 기술요소를 반복 시뮬레이션 하여 가장 경제적이고 효과적인 녹색기술 개선책을 제시 하고자 한다.

• 대한수학교육학회지:학교수학
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• 제18권3호
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• pp.571-587
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• 2016

남진영(2008a)은 학생의 수학적 구조의 학습을 돕기 위한 교사의 역할을 암묵적 지식의 현시자라고 제안하였다. 그러나 아직 암묵적 지식의 현시의 의미를 구체화한 연구는 부족하다. 이에 본 연구에서는 Watson & Mason(2015)의 제안한 예 구성 활동이 그 목표, 내용, 방법 면에서 암묵적 지식을 현시하는 한 가지 방식임을 보임으로써, 암묵적 지식의 현시의 의미를 구체화하고자 하였다. 첫째, 예 구성 활동을 통한 암묵적 지식의 현시는 암묵적 영역에 있는 수학적 구조의 학습을 목표로 한다. 둘째, 예 구성 활동을 통한 암묵적 지식의 현시는 예를 통해 변이 속에서 불변적인 요소를 인식함으로써 암묵적 영역에 있는 수학적 구조를 교육하고자 한다. 셋째, 예 구성 활동을 통한 암묵적 지식의 현시는 명시적 지식을 창의적으로 구성해보는 활동, 활동에 대한 반성 과정, 사회적 상호작용을 통해 암묵적 영역에 있는 수학적 구조를 교육하고자 한다. 따라서 예 구성 활동은 그 목표, 내용, 방법 면에서 암묵적 지식을 현시하는 구체적인 한 수업 방식으로 볼 수 있다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 추계 학술발표회논문집
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• pp.497-504
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• 2003

An optimal design method for hybrid structural control system of building structures subject to earthquake excitation is presented in this paper. Designing a hybrid structural control system nay be defined as a process that optimizes the capacities and configuration of passive and active control systems as well as structural members. The optimal design proceeds by formulating the optimization problem via a multi-stage goal programming technique and, then, by finding reasonable solution to the optimization problem by means of a goal-updating genetic algorithm. The process of the integrated optimization design is illustrated by a numerical simulation of a nine-story building structure subject to earthquake excitation. The effectiveness of the proposed method is demonstrated by comparing the optimally designed results with those of a hybrid structural control system where structural members, passive and active control systems are uniformly distributed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.4174-4190
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• 2019

IEC 62304 is a standard for the medical device software lifecycle. Developers must develop software that complies with all specifications in the standard for licensing. However, because the standard contains not only a large number of specifications, but also domain-specific information and association relationships between specifications, it requires considerable effort and time for developers to understand and interpret the standard. To support developers, this paper presents a method for extracting the contents of the IEC 62304 standard as a goal model, which is the core methodologies of requirements engineering. The proposed method analyzes the grammar of the standard to robustly extract complex structures and various information from standard specifications and define rules that extract goals and links from syntactic element units. We validated the actual extraction process for the standard document experimentally. Based on the extracted goal model, developers can intuitively and efficiently comply with the standard and track specific information within the medical software and standard domains.

• Asia pacific journal of information systems
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• 제9권1호
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• pp.193-209
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• 1999

Developing Information Systems is a process of decomposing the entire systems into sub systems and identifying a hierarchical structure among the sub systems. Diagrammatic representation of hierarchy is an essential part of systems development since the identified hierarchical structures are usually presented in diagrams. The main goal of this research is to identify the most effective ways of representing system structures using diagrams. In order to achieve the main goal, this study performed three phases of research. In the first step, a theoretical model was constructed to conceptually explain users' comprehension on diagrams. Then visual factors of diagrammatic representations were identified based on the diagrams used in systems development. Finally, three consecutive experiments were conducted to identify the impacts of visual factors on the level of users' comprehension. The results indicate that familiarity and affordance of diagrams affect the degree of comprehension about the diagrams, which is in turn influenced by the complexity of tasks and the types of hierarchies. This paper concludes with the limitations of the study results and implications in the development of information systems.

• 한국항해항만학회지
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• 제31권7호
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• pp.589-595
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• 2007

In the majority of previous studies on deformation of seabed structures using DEM, elements of structures have been assumed that it is composed with uniform materials or received fixed wave force, despite that actual submerged structures are composed with various size materials and influenced by complicated fluid field. The goal of this study is to develop a new model for analysis of seabed structure deformation using discontinuous structures composed with various size materials. As the first phase, a model using DEM and VOF, which can compute the deformation of submerged structures composed with various size materials, such as rubble mound structures, is proposed. A model test is carried out and then the validity of the model is discussed.

• Computers and Concrete
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• 제32권6호
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• pp.615-623
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• 2023

Crack detection is an essential method to ensure the safety of dam concrete structures. Low-quality crack images of dam concrete structures limit the application of neural network methods in crack detection. This research proposes a modified attentional mechanism model to reduce the disturbance caused by uneven light, shadow, and water spots in crack images. Also, the focal loss function solves the small ratio of crack information. The dataset collects from the network, laboratory and actual inspection dataset of dam concrete structures. This research proposes a novel method for crack detection of dam concrete structures based on the U-Net neural network, namely AF-UNet. A mutual comparison of OTSU, Canny, region growing, DeepLab V3+, SegFormer, U-Net, and AF-UNet (proposed) verified the detection accuracy. A binocular camera detects cracks in the experimental scene. The smallest measurement width of the system is 0.27 mm. The potential goal is to achieve real-time detection and localization of cracks in dam concrete structures.