• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.54-56
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• 2007

제주계통은 계통규모에 비해 전원용량이 큰 HVDC 제주연계선로와 단위기 용량이 큰 발전기들이 운전되고 있다. HVDC 2회선 동시 탈락이나, HVDC 미운전시 단위기 용량이 큰 발전기가 전력계통에서 탈락하면 제주계통 주파수는 급격히 저하되고 적절한 보호대책을 수립하지 않으면 전 계통 붕괴가 일어날 수도 있다. 본 논문은 저주파수 계전기에 의한 부하차단방식 적용시 고려하여야 할 조건과 제주계통 저주파수계전기에 의한 부하차단방식에 관해 기술하였다.

• International Journal of Computer Science & Network Security
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• v.23 no.3
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• pp.139-143
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• 2023

In this article we propose using mathematical models of signals in wireless communication systems with autocorrelation reception of modulated ultra-wideband signals. For the transmission of information content, the method of positional-time coding is used, in which each information bit is encoded by hundreds of ultrashort pulses that arrive within a certain sequence. Comparative analysis has shown that the best noise immunity of the systems considered in this paper is the communication system, which uses the time separation of the reference and information signals.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.12
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• pp.5095-5099
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• 2016

The relative lack of information on breast cancer etiology in Burkina Faso led us to undertake the present work to highlight risk factors. This prospective study was conducted using a questionnaire between January 2015 and February 2016 on women admitted to Yalgado OUEDRAOGO hospital, for consultation or supervision. The characteristics of multiparous breast cancer patients (n = 44) were compared with their non-multiparous counterparts (n = 36). The study found that increased risk of breast cancer among non-multiparous cases was related to body mass index (BMI) (p <0.001), age at menopause (p <0.004) and use of oral contraception (p <0.021) while abortion (p <0.002) was a risk factor among multiparous cases. These results suggest that even if multiparity is associated with a decreased risk in some women, avoidance of abortion during reproductive life should be recommended. The results provide preliminary information, which now need to be supplemented by survey of a larger sample in the national territory.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.4
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• pp.255-266
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• 2022

Background: A previous study reported the effectiveness and patient satisfaction in the dental emergency unit (DEU) of the Pitie Salpetrière Hospital in Paris before coronavirus disease 2019 (COVID-19). The same methodology was used during the COVID-19 pandemic to compare pain, anxiety, and patient satisfaction during the two periods. Methods: This prospective study was conducted in 2020 (NCT04354272) on adult patients. Data were collected on day zero (D0) on site and then by phone during the daytime on day one (D1), day three (D3), and day seven (D7). The primary objective was to assess the pain intensity at D1. Secondary objectives were to assess pain intensity at D3 and D7, anxiety intensity at D1, D3, and D7, and patient satisfaction. Patients were evaluated on a 0-10 numeric scale on D1, D3, and D7; mean scores were compared with non-parametric statistics (ANOVA, Dunn's). Results: A total of 445 patients were given the opportunity to participate in the study, and 370 patients consented. Seventy-one were lost during follow-up. Ultimately, 299 patients completed all the questionnaires and were included in the analysis. In the final sample (60% men, 40% women, aged 39 ± 14 years), 94% had health insurance. The mean pain scores were: D0, 6.1 ± 0.14; D1, 3.29 ± 0.16; D3, 2.08 ± 0.16; and D7, 1.07 ± 0.35. This indicates a significant decrease of 46%, 67%, and 82% at D1, D3, and D7, respectively, when compared to D0 (P < 0.0001). The mean anxiety scores were D0, 4.7 ± 0.19; D1, 2.6 ± 0.16; D3, 1.9 ± 0.61; and D7, 1.4 ± 0.15. This decrease was significant between D0 and D7 (ANOVA, P < 0.001). Perception of general health improved between D1 and D7. The overall satisfaction was 9.3 ± 0.06. Conclusion: DEU enabled a significant reduction in pain and anxiety with high overall satisfaction during COVID-19, which was very similar to levels observed pre-COVID-19 pandemic.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.11
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• pp.1554-1560
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• 2017

Prepare a lose of 765kV transmission route in power system operation condition, there are some Special Protection Scheme(SPS)s in Korean power system. These SPS can make some preselected generators are tripped to avoid generator overspeed. Because of many of the new large power plants are installed to existing power generation sites due to the siting problem, the number of generator tripped by SPS should be increased. But that can be a cause of system frequency change under the Under Frequency Relay(UFR) 1st pickup level 59.0Hz. Therefore generation constraint should be considered until new transmission lines are installed. In this paper, we propose the ESS application for generation constraint mitigation by frequency damping control of ESS. To analysis an effect of ESS application, we use PSS/E dynamic simulation tool, CBEST model and controller model. The proposed ESS application is applied to the empirical Korean power system.

• The Korean Journal of Food And Nutrition
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• v.37 no.1
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• pp.1-8
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• 2024

This study investigated the effect of Lactiplantibacillus plantarum JSA22-fermented rice drinks on dextran sodium sulfate (DSS)-induced colitis in mice. Twenty-four mice were randomly assigned; No colitis (Con), colitis with tap water (DSS-only), colitis with unfermented rice (DSS-UFR), and colitis with fermented rice (DSS-FR). After inducing colitis with 2% DSS for 5 days, they were given Tap water, UFR drink, or FR drink for an additional 6 days. The DSS-FR group had significantly lower Disease Activity Index (DAI) scores compared to the DSS-only group, but no significant difference with the DSS-UFR group. Colon length was reduced in the DSS-only group. The DSS-only group had significantly higher IL-6 mRNA levels compared to the Con group, while the DSS-FR groups showed significantly lower IL-6 mRNA levels compared to the DSS-only group. These results suggest that rice drinks fermented with Lactiplantibacillus Plantarum JSA22 ameliorate the severity of DSS-colitis, by potentially reducing proinflammatory cytokines.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.1
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• pp.29-37
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• 1985

During Severe emergencies which result in the case of outage of large generator units, an automatic underfrequency protection scheme can prevent the system frequency from decaying and improve the system stability. This paper presents methods and results of a study on the optimum load shedding scheme which covering as follows. 1) Detail representation of governor model 2) Determination of optimum load shedding amount 3) Selection of action time settings of UFR 4) Comparsson of load shedding programs By this study, the optimum system operating method was recommended for reliable operation of power system.

• Bulletin of the Korean Mathematical Society
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• v.50 no.6
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• pp.1923-1936
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• 2013

We prove that the intrinsic square functions including Lusin area integral and Littlewood-Paley $g^*_{\lambda}$-function as defined by Wilson, are bounded in a class of function spaces include weighted Morrey spaces. The corresponding commutators generated by BMO functions are also considered.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.521-522
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• 2007

본 논문은 Multi-agent 이론을 적용하여 저주파수 계전 알고리즘을 설계하는 방법을 제안하였다. 먼저 저주파수 계전에 필요한 사항을 알아보았다. 그 다음으로 현재 계통에 적용된 부하차단을 알아보고 이를 개선할 수 있는 Multi-agent 이론을 적용한 저주파수 계전 방법을 선택하여 그 방법의 적용 가능성을 제시하였다.

• Bulletin of the Korean Mathematical Society
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• v.61 no.2
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• pp.291-299
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• 2024

We study some factorization properties of the idealization R(+)M of a module M in a commutative ring R which is not necessarily a domain. We show that R(+)M is ACCP if and only if R is ACCP and M satisfies ACC on its cyclic submodules. We give an example to show that the BF property is not necessarily preserved in idealization, and give some conditions under which R(+)M is a BFR. We also characterize the idealization rings which are UFRs.