• The Korean Journal of Emergency Medical Services
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• v.24 no.1
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• pp.37-55
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• 2020

Purpose: The purpose of this study was to provide basic data for improving the response capacity of 119 EMS systems by analyzing the effects of particulate matter on cardio-cerebrovascular and respiratory symptoms in the pre-hospital stage. Methods: We examined 46,389 patients who transferred to the hospital with complaints of cardiopulmonary arrest and cardio-cerebrovascular and respiratory symptoms by 119 ambulances in Incheon from 2016 to 2018. Results: The probability of 119 emergency dispatch for patients with cardiopulmonary arrest increased 2.8-4.0% from the day of symptom onset until two days before hospital presentation as particulate matter 10㎛ or less in diameter(PM₁₀) increased by 10㎍/㎥ (OR=1.028; 95% CI=1.014-1.041, p=0.000, lag 0), (OR=1.040; 95% CI=1.024-1.056, p=0.000, lag 1), (OR=1.032; 95% CI=1.016-1.049, p=0.000, lag 2). Meanwhile, emergency dispatch increased 3.6-6.1% for PM_2.5 in creased by 10㎍/㎥ (OR=1.046; 95% CI=1.024-1.068, p=0.000, lag 0), (OR=1.061; 95% CI=1.035-1.088, p=.000, lag 1), and (OR=1.036; 95% CI=1.010-1.063, p=0.006, lag 2). Conclusion: Emergency medical technicians (EMTs) who respond to 119 calls should rapidly and accurately evaluate patients and provide professional emergency care by identifying the characteristics of the vulnerable groups relative to particulate matter size. To prevent the occurrence and exacerbation of symptoms caused by particulate matter, EMTs should be prepared and equipped with a response system for high particulate matter in the EMS system.

• Journal of the Korea Society of Computer and Information
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• v.17 no.11
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• pp.189-196
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• 2012

This paper proposes Swap algorithm for solving Dynamic Economic Dispatch (DED) problem. The proposed algorithm initially balances total load demand $P_d$ with total generation ${\Sigma}P_i$ by deactivating a generator with the highest unit generation cost $C_i^{max}/P_i^{max}$. It then swaps generation level $P_i=P_i{\pm}{\Delta}$, (${\Delta}$=1.0, 0.1, 0.01, 0.001) for $P_i=P_i-{\Delta}$, $P_j=P_j+{\Delta}$ provided that $_{max}[F(P_i)-F(P_i-{\Delta})]$ > $_{min}[F(P_j+{\Delta})-F(P_j)]$, $i{\neq}j$. This new algorithm is applied and tested to the experimental data of Dynamic Economic Dispatch problem, demonstrating a considerable reduction in the prevalent heuristic algorithm's optimal generation cost and in the maximization of economic profit.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.255-262
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• 2015

In the absence of a deterministic algorithm for economic load dispatch optimization problem (ELDOP), existing algorithms proposed as solutions are inevitably non-deterministic heuristic algorithms. This paper, therefore, proposes a balance-and-swap algorithm to solve an ELDOP. Firstly, it balances the initial value to ${\Sigma}P_i=P_d$ by subsequently reducing power generation for each adult-step and baby-step and selects the minimum cost-generating method. Subsequently, it selects afresh the minimum cost-generating method after an optimization of the previously selected value with adult-step baby-step swap and giant-step swap methods. Finally, we perform the $P_i{\pm}{\beta}$, (${\beta}=0.1,0.01,0.001,0.0001$) swap. When applied to the 3 most prevalently used economic load dispatch problem data, the proposed algorithm has obtained improved results for two and a result identical to the existing one for the rest. This algorithm thus could be applied to ELDOP for it has proven to consistently yield identical results and to be applicable to all types of data.

• Journal of Korea Spatial Information System Society
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• v.10 no.1
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• pp.41-49
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• 2008

This paper presents a data analysis method for the taxi telematics system which generates a greate deal of location history data. By the record consist of the basic GPS receiver-generated fields, device-added fields such as taxi operation status, and framework-attached fields such as matched link Identifier and position ratio in a link, each taxi can be represented by a state diagram. The transition and the state definition enable us to efficiently extract such information as pick-up time, pick-up distance, dispatch time, and dispatch distance. The analysis result can help to verify the efficiency of a specific taxi dispatch algorithm, while the analysis framework can invite a new challenging service including future traffic estimation, trajectory clustering, and so on.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.24-35
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• 2016

Emergency Vehicle Preemption(EVP) is an operation method which helps to improve response condition of Emergency Vehicle(EV) and it has not yet been introduced in Korea. In order to implement the system, it requires step-by-step plan and selecting a priority area for trial operation. Since a municipal government such as Seoul is too large so it is limited in time and cost to analyze the whole area. Therefore, quantitative and effective selection method for priority area is critical. The aim of this study is to propose a selection method of implementation area for EVP system using the dispatch data analysis. This study also determined the priority area for EVP implementation by analyzing the dispatch data in Seoul and conducted a simulation to evaluate the effects of implementing EVP.

• Annals of Occupational and Environmental Medicine
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• v.34
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• pp.37.1-37.15
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• 2022

Background: This study investigated the effect of dispatch frequency on blood cadmium levels and the effect of blood cadmium levels on hypertension in male firefighters in a metropolitan city. Methods: We conducted a retrospective longitudinal study of male firefighters who completed the regular health checkups, including a health examination survey and blood cadmium measurements. We followed them for 3 years. To investigate the effect of dispatch frequency on blood cadmium levels and the effect of blood cadmium levels on hypertension, we estimated the short-term (model 1) and long-term (model 2) effects of exposure and hypothesized a reversed causal pathway model (model 3) for sensitivity analysis. Sequential conditional mean models were fitted using generalized estimating equations, and the odds ratios (ORs) and the respective 95% confidence intervals (CIs) were calculated for hypertension for log-transformed (base 2) blood cadmium levels and quartiles. Results: Using the lowest category of dispatch frequency as a reference, we observed that the highest category showed an increase in blood cadmium levels of 1.879 (95% CI: 0.673, 3.086) ㎍/dL and 0.708 (95% CI: 0.023, 1.394) ㎍/dL in models 2 and 3, respectively. In addition, we observed that doubling the blood cadmium level significantly increased the odds of hypertension in model 1 (OR: 1.772; 95% CI: 1.046, 3.003) and model 3 (OR: 4.288; 95% CI: 1.110, 16.554). Using the lowest quartile of blood cadmium levels as a reference, the highest quartile showed increased odds of hypertension in model 1 (OR: 2.968; 95% CI: 1.121, 7.861) and model 3 (OR: 33.468; 95% CI: 1.881, 595.500). Conclusions: We found that dispatch frequency may affect blood cadmium levels in male firefighters, and high blood cadmium levels may influence hypertension in a dose-response manner.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.726-737
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• 2017

The use of energy storage systems (ESSs) has become a feasible solution to solve the wind power intermittency issue. However, the use of ESSs increases the system cost significantly. In this paper, an optimal power flow control scheme to minimize the ESS capacity is proposed by using the zero-phase delay low-pass filter which can eliminate the phase delay between the dispatch power and the wind power. In addition, the filter time constant is optimized at the beginning of each dispatching interval to ensure the fluctuation mitigation requirement imposed by the grid code with a minimal ESS capacity. And also, a short-term power dispatch control algorithm is developed suitable for the proposed power dispatch based on the zero-phase delay low-pass filter with the predetermined ESS capacity. In order to verify the effectiveness of the proposed power management approach, case studies are carried out by using a 3-MW wind turbine with real wind speed data measured on Jeju Island.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1023-1030
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• 2007

This paper presents a new and efficient approach for solving the economic dispatch (ED) problems with nonconvex cost functions using particle swarm optimization (PSO). Although the PSO is easy to implement and has been empirically shown to perform well on many optimization problems, it may easily get trapped in a local optimum when solving problems with multiple local optima and heavily constrained. This paper proposes an improved PSO, which combines the conventional PSO with chaotic sequences (CPSO). The chaotic sequences combined with the linearly decreasing inertia weights in PSO are devised to improve the global searching capability and escaping from local minimum. To verify the feasibility of the proposed method, numerical studies have been performed for two different nonconvex ED test systems and its results are compared with those of previous works. The proposed CPSO algorithm outperforms other state-of-the-art algorithms in solving ED problems, which consider valve-point and multi-fuels with valve-point effects.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.74
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• pp.1-23
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• 2017

The buyer must examine the goods, or cause them to be examined, within as short a period as is practicable in the circumstances. Article 38 lays down a fundamental principle that requires the buyer to examine quickly the goods delivered by the seller. Article 38 (1) provides that the examination be made within as short a period as practicable in the circumstances. The goods have to be examined within as short a period as is practicable in the circumstances. The rule is based on the fundamental idea of reasonableness, meaning that the buyer must examine the goods as soon as reasonably possible. It may be said that the buyer should act reasonably fast. Article 38 (2), (3) concerns sales involving carriage of the goods, where the seller's obligation to deliver consists in handing the goods over to the first carrier for transmission to the buyer. In this case the buyer is generally able to examine the goods only after they have come to destination. Article 38 (3) takes into account the case where the buyer redirects the goods in transit or re-dispatches them to another destination. Redirection in transit occurs when the destination is changed before the goods are received by the buyer. The buyer could re-dispatch the goods without having them unloaded, or re-dispatch them through another carrier.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1485-1495
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• 2009

This paper presents a novel approach to economic dispatch (ED) with nonconvex fuel cost function as combinatorial optimization problems (COP) while most of the conventional researches have been developed as function optimization problems (FOP). One nonconvex fuel cost function can be divided into several convex fuel cost functions, and each convex function can be regarded as a generation type (G-type). In that case, ED with nonconvex fuel cost function can be considered as COP finding the best case among all feasible combinations of G-types. In this paper, a genetic algorithm is applied to solve the COP, and the ${\lambda}-P$ function method is used to calculate ED for the fitness function of GA. The ${\lambda}-P$ function method is reviewed briefly and the GA procedure for COP is explained in detail. This paper deals with two kinds of ED problems, namely ED with multiple fuel units (EDMF) and ED with prohibited operating zones (EDPOZ). The proposed method is tested for all the ED problems, and the test results show an improvement in solution cost compared to the results obtained from conventional algorithms.