• Journal of Information Processing Systems
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• 제14권4호
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• pp.1010-1032
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• 2018

Recent advances in medical science have made people live longer, which has affected many aspects of life, such as caregiver burden, increasing cost of healthcare, increasing number of disabled and depressive disorder persons, and so on. Researchers are now focused on elderly living assistance services in smart home environments. In recent years, assisted living technologies have rapidly grown due to a faster growing aging society. Many smart devices are now interconnected within the home network environment and such a home setup supports collaborations between those devices based on the Internet of Things (IoT). One of the major challenges in providing elderly living assistance services is to consider each individual's requirements of different needs. In order to solve this, the virtualization of physical things, as well as the collaboration and composition of services provided by these physical things should be considered. In order to meet these challenges, Web of Objects (WoO) focuses on the implementation aspects of IoT to bring the assorted real world objects with the web applications. We proposed a semantic modelling technique for manual and semi-automated service composition. The aim of this work is to propose a framework to enable RESTful web services composition using semantic ontology for elderly living assistance services creation in WoO based smart home environment.

• 한국컴퓨터산업학회논문지
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• 제6권3호
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• pp.529-538
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• 2005

AUML(Agent Unified Modeling Language)은 에이전트 소프트웨어 시스템의 명세화, 시각화, 생성을 목적으로 하는 언어이다. 본 연구에서는 소프트웨어의 복잡화, 대형화 추세에 자동화 응용 프로그램 생성 시스템들 중의 하나인 Together를 Agent의 BDI에 응용시키고 이를 컴포넌트 시스템의 상호 운영성에 대하여 고찰한다. 상호 운용성은 컴포넌트간의 데이터 교환에 의해 이루어지며 컴포넌트의 타입이 다르더라도 서로 협력할 수 있는 표준 명세서(FIPA:Foundation for Inteligent Physical Agent)를 기반으로 ACL 메시지, 그리고 프로토콜을 사용하며 이를 객체지향 모델링을 통한 메타모델기반 등을 이용하여 구현 시 오류를 최소화하는 방법과 정확성과 일관성에 관하여 연구한다.

• Advances in aircraft and spacecraft science
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• 제3권1호
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• pp.95-112
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• 2016

This paper presents the free vibration analysis of damaged beams by means of 1D (beam) advanced finite element models. The present 1D formulation stems from the Carrera Unified Formulation (CUF), and it leads to a Component-Wise (CW) modelling. By means of the CUF, any order 2D and 1D structural models can be developed in a unified and hierarchical manner, and they provide extremely accurate results with very low computational costs. The computational cost reduction in terms of total amount of DOFs ranges from 10 to 100 times less than shell and solid models, respectively. The CW provides a detailed physical description of the real structure since each component can be modelled with its material characteristics, that is, no homogenization techniques are required. Furthermore, although 1D models are exploited, the problem unknown variables can be placed on the physical surfaces of the real 3D model. No artificial surfaces or lines have to be defined to build the structural model. Global and local damages are introduced by decreasing the stiffness properties of the material in the damaged regions. The results show that the proposed 1D models can deal with damaged structures as accurately as a shell or a solid model, but with far lower computational costs. Furthermore, it is shown how the presence of damages can lead to shell-like modal shapes and torsional/bending coupling.

• Geomechanics and Engineering
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• 제18권3호
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• pp.247-258
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• 2019

Soil strength and failure surface geometry directly influence magnitudes of passive earth thrust acting on geotechnical retaining structures. Accordingly, it is expected that as long as the shape of the failure surface geometry and strength parameters of the backfill are known, magnitudes of computed passive earth thrusts should be highly accurate. Building on this premise, this study adopts conventional method of slices for calculating passive earth thrust and combines it with equations for estimating failure surface geometries based on in-situ stress state and density. Accuracy of the proposed method is checked using the results obtained from small-scale physical retaining wall model tests. In these model tests, backfill was prepared using either air pluviation or compaction and different backfill relative densities were used in each test. When the calculated passive earth thrust magnitudes were compared with the measured values, it was noticed that the results were highly compatible for the tests with pluviated backfills. On the other hand, calculated thrust magnitudes significantly underestimated the measured thrust magnitudes for those tests with compacted backfills. Based on this observation, a new approach for the calculation of passive earth pressures is developed. The proposed approach calculates the magnitude and considers the influence of locked-in stresses that are the by-products of the backfill preparation method in the computation of lateral earth forces. Finally, recommendations are given for any geotechnical application involving the compaction of granular bodies that are equally applicable to physical modelling studies and field construction problems.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1122-1129
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• 2022

The concept of Digital Twin (DT) has been receiving an increasing amount of attention in the construction management and building engineering research domains. Although the benefits of DT are evident, confusion with regards to the concept of DTs and its relationship with others such as Cyber-Physical Systems (CPS), Building Information Modelling (BIM) and Internet of Things (IoT) remains. This paper aims to help allay this confusion through an in-depth analysis of the definition of DT and its unique characteristics. As such, a review of the past and current definitions of DT and CPS in various domains is performed. An analysis is then conducted to identify the overlaps between the definition of DT with CPS, as well as with BIM and IoT. Finally, given the relatively closer resemblances between DT and CPS, a set of four distinct dimensions enabling their comparative analysis and highlighting their shared and unique characteristics is discussed. This paper contributes to the existing literature by exploring the definition of DT and presenting two original conceptualizations that help further refine the concept of DT in the construction and management and building engineering domain.

• International Journal of Automotive Technology
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• 제7권4호
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• pp.459-468
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• 2006

The objective of this paper is the development of the forward-looking dynamic simulation model of a hybrid electric vehicle(HEV) for a fuel economy study. The specification of the vehicle is determined based on two factors, engine peak power to curb weight ratio and specific engine power. The steady state efficiency models of the powertrain components are explained in detail. These include a spark ignition direct injection(SIDI) engine, an integrated starter alternator(ISA), and an infinitely variable transmission(IVT). The paper describes the integration of these models into a forward facing dynamic simulation diagram using the AMESim environment. Appropriate vehicle and driver models have been added and described. The controller was designed in Simulink and was combined with the physical powertrain model by the co-simulation interface. Finally, the simulation results of the HEV are compared with those of a baseline vehicle in order to demonstrate the fuel economy potential. Results for the vehicle speed error and the fuel economy over standard driving cycles are illustrated.

• 호남수학학술지
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• 제37권2호
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• pp.245-252
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• 2015

This paper is in continuation of the paper very recently published [New Laplace transforms of Kummer's confluent hypergeometric functions, Math. Comp. Modelling, 55 (2012), 1068-1071]. In this paper, our main objective is to show one can obtain so far unknown Laplace transforms of three rather general cases of generalized hypergeometric function $_2F_2(x)$ by employing generalized Watson's, Dixon's and Whipple's summation theorems for the series $_3F_2$ obtained earlier in a series of three research papers by Lavoie et al. [5, 6, 7]. The results established in this paper may be useful in theoretical physics, engineering and mathematics.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.334-337
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• 1996

This is a paper intended for initial stage of vehicle modeling and design. The needs to determine a variety of vehicle suspension parameters required for initial design has been difficult and time-consuming task. In order to facilitate a concise and efficient presentation of initial vehicle design procedure, this paper uses a mathematical model and physical geometry. Vehicle model consists of dimensions, inertias and mechanical constants. These vehicle model parameters divided into several categories : basic parameters, coefficients and constants, design specification, spring and damper, bush stiffness, stabilizer bar, suspension geometry, tire, and vehicle weights of various design condition. This paper uses a vehicle design fundamental (VDF) program running under Windows 95 graphical interface. The features of VDF will be briefly outlined in this paper.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.21-24
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• 2014

In the entrained-flow coal gasifier, coal ash turns into a molten slag most of which deposits onto the wall to form liquid and solid layers. Critical viscosity refers to the viscosity at the interface of the two layers. The slag layers play an important role in protecting the wall from physical/chemical attack from the hot syngas and in continuously discharging the ash to the slag tap at the bottom of the gasifier. For coal with high ash melting point and slag viscosity, CaO-based flux is added to coal to lower the viscosity. This study evaulates the effect of critical viscosity temperature and ash/flux ratio on the slag behavior using numerical modelling in a commercial gasifier. The changes in the slag layer thickness, heat transfer rate, surface temperature and velocity profiles were analyzed to understand the underlying mechanism of slag flow and heat transfer.

• 한국조리학회지
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• 제23권1호
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• pp.10-18
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• 2017

This study examined the positive impact of workplace harassment on the employees' counterproductive work behavior at deluxe hotel in Seoul and Tokyo. The study verified a differentiated influence based on the nationality of the employees. The hypothesized relationships in the model were tested simultaneously by using structural equation modelling. First, isolation/exclusion (${\beta}=.403$), disrespectful behavior (${\beta}=.312$), physical aggression (${\beta}=.245$), and verbal aggression (${\beta}=.133$) had a positive impact on counterproductive work behavior. However, threats/bribes (${\beta}=.091$) did not show a significant impact. Second, no significant moderating effect based on employees' nationality (Korean versus Japanese) was observed in the relationship between the five workplace harassment factors and CWB. This study will investigate workplace harassment perceived by deluxe hotel employees in Korea and Japan, and the obtained data can also be used to help identify realistic plans to reduce workplace harassment between bosses and subordinates at an organizational level.