• The Korean Journal of Emergency Medical Services
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• v.25 no.1
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• pp.205-221
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• 2021

Purpose: This paper is to determine whether automatic defibrillators (AEDs) deployed across communities make a contribution to prevent death in patients with acute cardiac arrest out-of-hospital. Methods: A total of 30,179 cases of cardiac arrest investigation data from the Korea Centers for Disease Control and Prevention was matched to those on emergency medical statistics drawn from annual report for the 2018 Central Emergency Medical Center, and statistics from the National Statistical Office in 2018. Results: Multiple logistic regression analyses revealed that availability of emergency medical resources across associated with different survival rates at emergency room after taking variability of the patient's personal characteristics and episodic situational characteristics held constant. The survival rate was 1.71 times higher for patients living in communities with more than 105 AEDs avaiable per 100,000 inhabitants than for those living in communities with less than 55 AEDs. Conclusion: The survival-related factors of patients with acute cardiac arrest that occurred out-of-hospital were found to be associated with patients' and episodic situational characteristics. The hospital stage were found to be associated with patients characteristics and episodic situational characteristics, The variability of AED available in a community has an impact on survival rate after emergency room treatment.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.1135-1142
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• 2021

This study aims to examine the factors that determine bond yields in infrastructure companies listed on the Indonesia Stock Exchange. The research sample used 31 bonds issued by the company during the 2015-2019 period. The data analysis method to estimate the determinant of bond yield uses multiple regression models. The results prove that the increase in the coupon rate causes bond yields to increase, while the inflation rate has the opposite effect of decreasing bond yield. Interest rate, exchange rate, duration, and bond rating variables cannot affect the bond yield. The results of this study imply that investors will be interested in investing in bonds with better yields if the company has to set a higher coupon rate, especially in economic conditions that experience low inflation rates. Interest rates and exchange rates as macroeconomic variables have not been considered by investors in purchasing bonds. Bond characteristic factors, namely, the duration and rating of the bonds, are considered less important factors in bond investment decisions because they are more oriented towards getting higher yields. Therefore, further research needs to be explored further related to the behavior of Indonesian bond investors who may have different characters from investors in other countries.

• Journal of Korean society of Dental Hygiene
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• v.23 no.1
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• pp.83-89
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• 2023

Objectives: This study aimed to examine the relationship between COVID-19-related depressive symptoms and oral health among Korean adolescents. Methods: Data from the 17th Korea Youth Risk Behavior Web-based Survey were used and analyzed by the chi-squared test, and multiple logistic regression analysis was performed using SPSS 21.0. The final study population comprised 54,835 individuals. Results: The rates of toothache, gingival bleeding, tooth fracture, and tooth sensitivity were 21.2, 19.1, 8.7, and 30.6%, respectively. The rates of equal, increased, and decreased COVID-19-related depressive symptoms were 53.4, 36.9, and 9.7%, respectively. The rates of toothache, gingival bleeding, and tooth sensitivity were significantly higher (49.0, 48.3, and 46.3%, respectively) in the increased depressive symptom group than that in the decreased depressive symptom group (7.7, 8.1, and 7.7%, respectively). After adjusting for gender, school grade, school record, household economic status, tooth brushing frequency, smoking habit, and alcohol consumption, the risks of toothache, gingival bleeding, and tooth sensitivity in the increased depressive symptom group were symptom group were 1.64 (95% CI: 1.51-1.78), 1.55 (95% CI: 1.43-1.68), and 1.77 (95% CI: 1.65-1.89), respectively. Conclusions: There was a significant increase in oral symptoms in the group with increased depressive symptoms.

• Biomedical Science Letters
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• v.18 no.3
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• pp.254-259
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• 2012

Infections involving Echinostoma hortense (E. hortense) are considered to more severe than infections caused by other heterophyids. Although parasite expulsion by host immune responses attenuates the symptoms of infection, the detailed mechanisms of the host immune response need to be determined, especially in local immune responses involving cytokine and immunoglobulin expressions. We infected BALB/c mice with E. hortense and examined recovery rates together with expressions of multiple cytokines and immunoglobulins in the villi and crypts of the small intestine using immunohistochemistry. We observed a close correlation between worm expulsion rates and cytokine/immunoglobulin expressions in E. hortense infected mice. This study contributes to an understanding of the relationship between the immune response and parasite expulsion in hosts.

• Journal of the military operations research society of Korea
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• v.17 no.2
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• pp.72-89
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• 1991

In transportation network problems, it is often desirable to select multiple number of the shortect paths. On problems of finding these paths, algorithms have been developed to choose single shortest path, k-shortest paths and k-shortest paths via p-specified nodes in a network. These problems consider the time as the main factor. In wartime, we must consider availability as well as time to determine the shortest transportation path, since we must take into account enemy's threat. Therefore, this paper addresses the problem of finding the shortest transportation path considering both time and availability. To accomplish the objective of this study, values of k-shortest paths are computed using the algorithm for finding the k-shortest paths. Then availabilties of those paths are computed through simulation considering factors such as rates of suffering attack, damage and repair rates of the paths. An optimal path is selected using any one of the four decision rules that combine the value and availability of a path.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.1-7
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• 2003

This paper considers an Integrated one-vendor multi-buyer production-inventory model where the vendor manufactures multiple products In lot at Her associated finite production rates In the model. It is allowed for earth product to be shipped In lot to the buyers before the whole product production is not completed yet. Each product lot is dispatched to the associated buyer In a number or shipments. The buyers consume their products at fixed rates. The objective is to the production and shipment schedules in the Integrated system. which minimizes the mean total annual cost per unit time. The mean total annual cost consists or production setup cost inventory holding cost and shipment cost. For the model, an Iterative optimal solution procedure with shipment consolidation policy incorporated is derived. It is then tested through numerical experiments to show how efficient and effective He shipment consolidation policy is.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.105-111
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• 2004

A total of 301 Thoroughbred mares were investigated the characteristics of breeding in the local areas in Jeju during the period from February 2000 to July 2001. The pregnancy rate and foaling rate in 143 mares were 93.0%, 72.0%, respectively, and mean gestational length was 339.3 days in 2000. The pregnancy rate in 158 mares was 86.7% in 2001. Mature follicles were ovulated in right(46.0%), left(45.2%), and bilateral(7.8%) ovary. The incidence of multiple pregnancies in 158 mares between 15 days and 45 days after mating were 89.3%(single), 10.1%(twin), and 0.6%(triple). The incidence of EED was 13.3%. Also uterine cyst and fluid had an bad influence on mare's pregnancy. These results suggest that regular monitoring of the pregnancies and maintaining of good uterine condition improve the pregnancy rates and foaling rates during breeding season.

• Journal of Information Processing Systems
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• v.16 no.5
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• pp.1048-1063
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• 2020

In this study, we propose a reinforcement learning agent to control the data transmission rates of nodes in carrier sensing multiple access with collision avoidance (CSMA/CA)-based wireless networks. We design a reinforcement learning (RL) agent, based on Q-learning. The agent learns the environment using the timeout events of packets, which are locally available in data sending nodes. The agent selects actions to control the data transmission rates of nodes that adjust the modulation and coding scheme (MCS) levels of the data packets to utilize the available bandwidth in dynamically changing channel conditions effectively. We use the ns3-gym framework to simulate RL and investigate the effects of the parameters of Q-learning on the performance of the RL agent. The simulation results indicate that the proposed RL agent adequately adjusts the MCS levels according to the changes in the network, and achieves a high throughput comparable to those of the existing data transmission rate adaptation schemes such as Minstrel.

• Korean Management Science Review
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• v.31 no.3
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• pp.13-26
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• 2014

This paper considers an integrated one-vendor multi-buyer production-inventory model where the vendor manufactures multiple products in lot at their associated finite production rates. In the model, it is allowed for each product to be shipped in lot to the buyers even before the whole product production is not completed yet. Each product lot is dispatched to the associated buyer in a number of shipments. The buyers consume their products at fixed rates. The objective is to the production and shipment schedules in the integrated system, which minimizes the total cost per unit time. The total cost consists of production setup cost, inventory holding cost and shipment cost. For the model, an iterative optimal solution procedure with shipment consolidation policy incorporated. It is then tested through numerical experiments to show how efficient and effective the shipment consolidation policy is.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1428-1431
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• 2002

It is general opinion that the future mobile multimedia networks will use different standards and a prospective solution to this problem will be software defined radio (SDR) techniques. SDR provides the flexibility to support multiple air interfaces and signal processing functions at the same time. Especially, digital signal processors and FPGAs are widely used for implementation of these adaptive and flexible functions of a baseband modem for SDR applications. Also, it is known that the modulation schemes of OCQPSK (Orthogonal Complex QPSK) and HPSK (Hybrid PSK) are used for IMT-2000 services of cdma2000 and WCDMA, respectively. Thus, in this paper, we design and implement an OCQPSK / HPSK modem using a DSP chip of Texas Instrument's TMS320C6701. One modulation scheme is operated by adaptive selection between the two schemes and 5 physical traffic channels differentiated by orthogonal codes are implemented in one DSP chip and each channel has 1Mbps data rates and 8Mcps chip rates.