• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.138-149
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• 2016

Quality function deployment (QFD) is a widely adopted customer-oriented product development methodology by translating customer requirements (CRs) into technical attributes (TAs), and subsequently into parts characteristics, process plans, and manufacturing operations. A main activity in QFD planning process is the determination of the target levels of TAs of a product so as to achieve a high level of customer satisfaction using the data or information included in the houses of quality (HoQ). Gathering the information or data for a HoQ may involve various inputs in the form of linguistic data which are inherently vague, or human perception, judgement and evaluation for the information and data. This research focuses on how to deal with this kind of impreciseness in QFD optimization. In this paper, it is assumed as more realistic situation that the values of TAs are taken as discrete, which means each TA has a few alternatives, as well as the customer satisfaction level acquired by each alternative of TAs and related cost are determined based on subjective or imprecise information and/or data. To handle these imprecise information and/or data, an approach using some basic definitions of fuzzy sets and the signed distance method for ranking fuzzy numbers is proposed. An example of a washing machine under two-segment market is provided for illustrating the proposed approach, and in this example, the difference between the optimal solution from the fuzzy model and that from the crisp model is compared as well as the advantage of using the fuzzy model is drawn.

• The Korean Journal of Emergency Medical Services
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• v.27 no.2
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• pp.91-111
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• 2023

Purpose: This study aims to compare 119 emergency medical services (EMS) in South Korea and Japan to provide essential data for EMS improvement in South Korea. Methods: Recent data and regulations on firefighting and EMS in South Korea and Japan were analyzed and compared. Results: South Korea follows a centralized approach to EMS, whereas Japan operates with autonomous bodies that establish their own criteria. Japan considers more regional variables than South Korea. In South Korea, there are shortages in fire station deployment among the 119 emergency medical resources in certain regions, leading to significant regional disparities. South Korea has a larger population served by its 119 emergency medical resources with a higher workload and dispatch numbers than Japan. The percentage of non-transported patients among the total number of dispatches was higher in South Korea. Conclusion: Increasing the number of medical professionals and ambulances per population to the level of Japan to reflect local conditions and include various underlying variables such as daytime population, aging, and emergency dispatch conditions in the deployment of 119 emergency resources, and to reduce the deployment gap between regions, will contribute to improving the performance of the South Korea EMS system.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.3
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• pp.192-205
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• 2007

The objective of this study was to investigate the optimal shapes and arrangements of sinkers attached to net cages to prevent their deformation in a current. A series of model experiments were conducted in a circulating water channel, using 5 different types of sinker(high-weighted ball, low-weighted ball, columntype, egg-shaped and iron bar-framed) and 2 types of square net cage constructed from both Nylon Raschel netting and Nylon knotted netting, on a 1/20th scale. The deflection of the model nets against the flow was smallest with the iron bar-framed weight compared to the other four types of sinker. It was expected that the optimal shapes of sinkers would be either the ball or egg-shape; however, iron bar-framed weight actually had larger drag forces. The dispersed deployment of sinkers on the bottom frames of model net cages performed better with relatively slow flows, while the concentrated deployment at 4 corners functioned better with relatively fast flows, in preventing the nets from becoming severely deformed. The deformation of the net cages was larger for the Nylon knotted netting than the Nylon Raschel netting. With respect to flow resistance, the Nylon Raschel netting, rather than the Nylon knotted netting, was more suitable for construction of net cages.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.228-231
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• 2015

In power system research fields, one of current key issues is the construction and commercialization of micro grid site which is called green island, carbon zero island, energy independent island, building micro grid, etc. and various affiliated technologies have been being vigorously developed to realize. In addition, various researches about electric vehicles (EVs) are in progress and it is expected to penetrate rapidly with the next a few years. Some new load models should be developed integrating with electric vehicle loads because the EVs' deployment could cause the change of load composition rate on power system planning and operations. EVs are also resources for micro grid as well as distributed generation and demand response so that various supply and demand side resources should be considered for micro grid researches. In this paper, the load composition rate of residential sectors is prospected considering the deployment of EVs and the resource configuration of micro grid is optimized based on net present cost. In the optimization, the load patten of case studies includes EV's charging characteristics and various cases are simulated comparing micro grid environment and normal condition. HOMER is used to compare various cases and economic effects.

• Journal of Environmental Science International
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• v.23 no.7
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• pp.1307-1320
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• 2014

A number of problems associated with environmental noises in urban areas have significantly been considered. Specific measurement and estimation of the environmental noise became a primary issue in local governments. Environmental noise monitoring system is required in order to estimate and verify the a city noise map. However, current monitoring positions may not perfectly represent and incorporate many different view points, such as districts of a city, different utilizations of a city by the law, populations, and classifications and traffics of roads. In addition, scientific method to provide specific noise monitoring positions my not be avaliable in current literature. For this reason, the primary objective of this paper is to propose a new method for introducing a number of monitoring positions in the entire city. First, the quality function deployment (QFD) method was utilized to simultaneously represent both districts and utilizations of a city. Second, a new algorithm to find a number of monitoring positions was proposed by compromising many different view points: populations, classifications of roads and areas, and traffics of roads. Finally, the proposed monitoring positions and a sample noise map was provided for verification purposes. Based on these results, the proposed algorithm including the QFD concept may successfully provide specific noise monitoring positions by simultaneously consider may different view points and requirements of a city.

• ETRI Journal
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• v.40 no.3
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• pp.291-302
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• 2018

The deployment of an incremental hybrid decode-amplify and forward relaying scheme is a promising and superior solution for cellular networks to meet ever-growing network traffic demands. However, the selection of a suitable relaying protocol based on the signal-to-noise ratio threshold is important in realizing an improved quality of service. In this paper, an incremental hybrid relaying protocol is proposed using polar codes. The proposed protocol achieves a better performance than existing turbo codes in terms of capacity. Simulation results show that the polar codes through an incremental hybrid decode-amplify-and-forward relay can provide a 38% gain when ${\gamma}_{th(1)}$ and ${\gamma}_{th(2)}$ are optimal. Further, the channel capacity is improved to 17.5 b/s/Hz and 23 b/s/Hz for $2{\times}2$ MIMO and $4{\times}4$ MIMO systems, respectively. Monte Carlo simulations are carried out to achieve the optimal solution.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.62-63
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• 2016

Existing studies relative to enhancing sustainability of earth-work are mainly involved in the performance of construction equipments. They assume that there is no variation of the engine power and fuel consumption and classify the dozer operation into working and idle conditions. They enable to find the most eco-friendly equipment fleet deployment plan. However, they are confined in that they do not provide a measure to assess the sustainability of the operation plan and suggest optimal alternative(s). This paper presents a method that identifies an optimal dozer operation plan that assures sustainability by reducing fuel consumption of the equipment. The method computes the dozer operation productivity using engine-torque-output map provided by equipment manufacturers. Indeed, it identifies the eco-dozing operation that minimizes fuel consumption and maximizes the target productivity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.2914-2935
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• 2016

With the increasing popularization of cloud computing, how to reduce physical energy consumption and increase resource utilization while maintaining system performance has become a research hotspot of virtual machine deployment in cloud platform. Although some related researches have been reported to solve this problem, most of them used the traditional heuristic algorithm based on greedy algorithm and only considered effect of single-dimensional resource (CPU or Memory) on energy consumption. With considerations to multi-dimensional resource utilization, this paper analyzed impact of multi-dimensional resources on energy consumption of cloud computation. A multi-dimensional resource constraint that could maintain normal system operation was proposed. Later, a novel virtual machine deployment method (NVMDM) based on improved particle swarm optimization (IPSO) and Euclidean distance was put forward. It deals with problems like how to generate the initial particle swarm through the improved first-fit algorithm based on resource constraint (IFFABRC), how to define measure standard of credibility of individual and global optimal solutions of particles by combining with Bayesian transform, and how to define fitness function of particle swarm according to the multi-dimensional resource constraint relationship. The proposed NVMDM was proved superior to existing heuristic algorithm in developing performances of physical machines. It could improve utilization of CPU, memory, disk and bandwidth effectively and control task execution time of users within the range of resource constraint.

• Journal of Power Electronics
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• v.9 no.1
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• pp.100-108
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• 2009

Designing communication architecture for substation automation is a challenging and subtle task for visualizing substations in the digital world under the umbrella of IEC61850. Communication paradigms for substation automation are of critical importance because of two reasons; the communication arena is changing daily and opts for convenience and simple deployment at a lower migration cost and interoperability is one of the core constrains of IEC61850 for substation automation. This paper presents an analysis and outline of the crucial need for the deployment of Gigabit Ethernet in substations and also presents suggestions on how Ethernet technology can help in substation automation. Ethernet is one of the most pervasive communication technologies available and can provide a long term solution in the changing arena of communication. We have performed simulations in NS-2 to prove that our suggested communication paradigm is optimal in various regards with consideration of the constraints imposed by IEC61850.

• Smart Media Journal
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• v.8 no.4
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• pp.72-79
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• 2019

The automated demand response (DR) program encourages consumers to participate in grid operation by reducing power consumption or deferring electricity usage at peak time automatically. However, successful deployment of the automated DR program sphere needs careful assessment of appliances load profile (ALP). To this end, the recent method estimates frequency, consistency, and peak time consumption parameters of the daily ALP to compute their potential score to be involved in the DR event. Nonetheless, as the daily ALP is subject to varying with respect to the DR time ALP, the existing method could lead to an inappropriate estimation; in such a case, inappropriate appliances would be selected at the automated DR operation that effected a consumer comfort level. To address this challenge, we propose a more proper method, in which all the three parameters are calculated using ALP that overlaps with DR time, not the total daily profile. Furthermore, evaluation of our method using two public residential electricity consumption data sets, i.e., REDD and REFIT, shows that our energy management systems (EMS) could properly match a DR target. A more optimal selection of appliances for the DR event achieves a power consumption decreasing target with minimum comfort level reduction. We believe that our approach could prevent the loss of both utility and consumers. It helps the successful automated DR deployment by maintaining the consumers' willingness to participate in the program.