• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.614-621
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• 1999

In this paper, the analytical appproaches are presented for jointly determining the profit-miximizing configuration of the fault-tolerance real time modular cell manufacturing system. The transient(time-dependent) analysis of Markovian models is firstly applied to modular cell manufacturing system from a performability viewpoint whose modeling advantage lies in its ability to express the performance that truly matters - the user's perception of it - as well as various performance measures compositely in the context of application. The modular cells are modeled with hybrid decomposition method and then availability measures such as instantaneous availability, interval availability, expected cumulative operational time are evaluated as special cases of performability. In addition to this evaluation, sensitivity analysis of the entire manufacturing system as well as each machining cell is performed, from which the time of a major repair policy and the optimal configuration among the alternative configurations of the system can be determined. Secondly, the recovery policies from the machine failures by computing the minimal number of redundant machines and also from the task failures by computing the minimum number of tasks equipped with detection schemes of task failure and reworked upon failure detection, to meet the timing requirements are optimized. Some numerical examples are presented to demonstrate the effectiveness of the work.

• The Journal of Information Systems
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• v.25 no.2
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• pp.27-50
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• 2016

Purpose The purpose of this study is to examine the effect of the acceptance intention towards healthcare wearable device in Korea. Specifically, this study attempted to identify the relationships among the acceptance intention towards healthcare wearable device, technical characteristics and user's personal characteristic based on UTAUT(Unified Theory of Acceptance and Use of Technology) model. Design/methodology/approach For this purpose of research, we conducted against consumers who use the wearable devices and we collected data from 219 wearable device users. The analyses were conducted using SPSS and AMOS19.0 which is powerful structural equation modeling (SEM) software. Findings The main findings are as followed; First, functional diversity, wearability, trend sensitivity and health perception are significantly related to performance expectancy, while visual aesthetic and enjoyment are not significantly related. Second, performance expectancy and effort expectancy are significantly related to acceptance intention towards healthcare wearable device. Third, effort expectancy is significantly related to performance expectancy.

• Journal of the Korea Computer Graphics Society
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• v.18 no.4
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• pp.17-23
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• 2012

The convergence of IT technology and fashion is a marked trend in recent years induding sportswear, m-dress (mobile phone dress), and wearable computing. Despite continued research and record high development in the field, however, there still are unsettled issues like power supply, fit, washability and mobility when it comes to commercializing technological fashion product. In this context, this thesis is to propose feasible technology effectively applied to a portable bag. The first case is a bag designed to maximize sensitivity for a family who enjoys leisure activities often. The second one is a limited editionHaute Couture style bag targeting single women in their 20s and 30s. These two case studies are an attempt to demonstrate the possibility of applying wearable technology to a product design.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1589-1599
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• 2017

Field programmable gate arrays (FPGAs) are getting more attention in safety-related and safety-critical application development of nuclear power plant instrumentation and control systems. The high logic density and advancements in architectural features make static random access memory (SRAM)-based FPGAs suitable for complex design implementations. Devices deployed in the nuclear environment face radiation particle strike that causes transient and permanent failures. The major reasons for failures are total ionization dose effects, displacement damage dose effects, and single event effects. Different from the case of space applications, soft errors are the major concern in terrestrial applications. In this article, a review of radiation effects on FPGAs is presented, especially soft errors in SRAM-based FPGAs. Single event upset (SEU) shows a high probability of error in the dependable application development in FPGAs. This survey covers the main sources of radiation and its effects on FPGAs, with emphasis on SEUs as well as on the measurement of radiation upset sensitivity and irradiation experimental results at various facilities. This article also presents a comparison between the major SEU mitigation techniques in the configuration memory and user logics of SRAM-based FPGAs.

• KIEAE Journal
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• v.12 no.6
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• pp.69-75
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• 2012

Because the demand or sensitivity of users of space has an important influence on the direction of design concerning indoor greening, this study examined the customers' preferences and trends for use in this field. By analyzing the results, types of space for indoor greening that can be utilized as indoor greening design such as vegetation selection, space positioning, design types, etc. were derived. The research and analysis was set for living space, business space, commercial space and public space. For each space, there were vegetations in over 50% of the space, and in all the spaces, the majority of people were of the positive opinion. As the desired space for the introduction of indoor greening, high levels of preference were seen in the following areas: 'veranda' and 'living room' for the residential space; 'main work space' and 'resting space' for the office space; and 'rest area,' 'entrance area' and 'lobby area' for the public space and commercial space. The preference of each of the spaces displayed slightly different trends in accordance with the characteristics of space and users. If indoor greening space were to be designed for these spaces according to the types, which are derived from the preference levels examined in this study, it is deemed that the satisfaction levels of users of the spaces could be increased.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.823-825
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• 1996

This paper proposes a preventive maintenance scheduling system which is a user-friendly decision-making support system. The objective of the development of the package is to supply KEPCO's working experts with a useful tool for gaining a practical maintenance schedule. This program based on the MS Windows is made up of two main modules. The first is an interactive decision-making support module(IDSM). The main objective of this module is to provide various useful text and graphic information to users, and enable practicing engineers with sensitivity analysis of a targeting maintenance schedule. The second is a mathematical optimization module(MOM). In this module, the objective function of levelizing net reserve ratio with daily time-increment is optimized using the relaxation method.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.177-179
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• 2009

It is increased that need of broadband multimedia service to make useful environment for user and to support the operation of railway system. So study of integrated data transmission in a subway and railway is activated. The research deals with pass loss characteristics of 18GHz microwave that is assigned frequency of integrated data transmission in a subway and railway. It is used sample integrated transmission system in subway and railway of KRRI(korea railroad research Institute) at the tunnel and road. Specification of test sample system is blow. It use OFDM modulation, Wireless frequency is 18GHz and 19GHz, Maximum output power is 20dBm, Receive sensitivity is -90dBm. The pass loss exponent and standard variation of road and tunnel is analyzed.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.339-346
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• 2017

The Korea Adaptation Center for Climate Change (KACCC) located in Korea Environment Institute has serviced a climate change vulnerability assessment support tool (VESTAP) since 2014 in order to help local governments to establish their own adaptation plans. Owing to its easy usage, the VESTAP has been utilized by not only local governments but also academia for examination of climate change vulnerability in various fields. However, the KACCC has not suggested a standard usage how to compose indices for climate exposure, sensitivity, and adaptation capacity which are main components of vulnerability although the KACCC manages operation and application of the VESTAP. Many users had no choice but to compose indices based on their own interpretation on the components of vulnerability. This technical note suggests the standard usage of VESTAP by reevaluating some vulnerability assessments previously developed. This may help users to correctly compose indices for climate change vulnerability assessment, and may minimize possibility of inter-user inconsistency in definition of vulnerability assessments.

• Smart Media Journal
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• v.8 no.2
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• pp.80-85
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• 2019

Generally, interlayer noise is measured in decibels (A) in terms of free field. In this paper, we propose a measurement method of interlayer vibration acceleration in the diffusion field perspective. The proposed method can represent a vibration-embodied formula similar to the sensitivity of earthquake intensity when the natural vibration of apartment house is measured by acceleration with its average value of $20mm/s^2$ represented by an the geometric progression of radix. Based on this theory, this paper proposes a method to show the optimal user experience (UX) by applying the interlayer vibration acceleration of the epicenter to the system of human - computer interaction (HCI).

• Steel and Composite Structures
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• v.42 no.1
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• pp.59-74
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• 2022

This study introduces a general reliability-based, performance-based design framework to design frames regarding their uncertainties and user-defined design goals. The Iterative-R method extracted from the main framework can designate a proper R (i.e., response modification factor) satisfying the design goal regarding target reliability index and pre-defined probability of collapse. The proposed methodology is based on FEMA P-695 and can be used for all systems that FEMA P-695 applies. To exemplify the method, multiple three-dimensional, four-story steel special moment-resisting frames are considered. Closed-form relationships are fitted between frames' responses and the modeling parameters. Those fits are used to construct limit state functions to apply reliability analysis methods for design safety assessment and the selection of proper R. The frameworks' unique feature is to consider arbitrarily defined probability density functions of frames' modeling parameters with an insignificant analysis burden. This characteristic enables the alteration in those parameters' distributions to meet the design goal. Furthermore, with sensitivity analysis, the most impactful parameters are identifiable for possible improvements to meet the design goal. In the studied examples, it is revealed that a proper R for frames with different levels of uncertainties could be significantly different from suggested values in design codes, alarming the importance of considering the stochastic behavior of elements' nonlinear behavior.