• Title/Summary/Keyword: LBR

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Numerical analysis of melt migration and solidification behavior in LBR severe accident with MPS method

  • Wang, Jinshun;Cai, Qinghang;Chen, Ronghua;Xiao, Xinkun;Li, Yonglin;Tian, Wenxi;Qiu, Suizheng;Su, G.H.
    • Nuclear Engineering and Technology
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    • v.54 no.1
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    • pp.162-176
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    • 2022
  • In Lead-based reactor (LBR) severe accident, the meltdown and migration inside the reactor core will lead to fuel fragment concentration, which may further cause re-criticality and even core disintegration. Accurately predicting the migration and solidification behavior of melt in LBR severe accidents is of prime importance for safety analysis of LBR. In this study, the Moving Particle Semi-implicit (MPS) method is validated and used to simulate the migration and solidification behavior. Two main surface tension models are validated and compared. Meanwhile, the MPS method is validated by the L-plate solidification test. Based on the improved MPS method, the migration and solidification behavior of melt in LBR severe accident was studied furthermore. In the Pb-Bi coolant, the melt flows upward due to density difference. The migration and solidification behavior are greatly affected by the surface tension and viscous resistance varying with enthalpy. The whole movement process can be divided into three stages depending on the change in velocity. The heat transfer of core melt is determined jointly by two heat transfer modes: flow heat transfer and solid conductivity. Generally, the research results indicate that the MPS method has unique advantage in studying the migration and solidification behavior in LBR severe accident.

Soft Load Balancing Using the Load Sharing Over Heterogeneous Wireless Networks (이기종 무선 환경에서 Load sharing을 이용한 Soft Load Balancing 기술)

  • Son, Hyuk-Min;Lee, Sang-Hoon;Kim, Soo-Chang;Shin, Yeon-Seung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.7A
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    • pp.757-767
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    • 2008
  • Start Ongoing next generation networks are expected to be deployed over current existing networks, in the form of overlayed heterogeneous networks, in particular, in hot spot areas. Therefore, it will be necessary to develop an interworking technique such as load balancing, to achieve increased overall resource utilization in the various heterogeneous networks. In this paper, we present a new load balancing mechanism termed 'soft' load balancing where the IP(Internet Protocol) traffic of a user is divided into sub-traffic, each of which flows into a different access network. The terminology of soft load balancing involves the use of both load sharing and handover techniques. Through a numerical analysis, we obtain an optimal LBR (Load Balancing Ratio) for determining the volume of traffic delivered to each network over an overlayed multi-cell environment. Using the optimal LBR, a more reliable channel transmission can be achieved by reducing the outage probability efficiently for a given user traffic.

Cumulative live birth rate after up to three consecutive embryo transfer cycles in women with poor ovarian response

  • Kim, Se Jeong;Lee, Dayong;Kim, Seul Ki;Jee, Byung Chul;Kim, Seok Hyun
    • Clinical and Experimental Reproductive Medicine
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    • v.47 no.2
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    • pp.135-139
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    • 2020
  • Objective: In the present study, we aimed to retrospectively evaluate the cumulative live birth rate (LBR) after up to three consecutive embryo transfer (ET) cycles, either fresh or frozen, in women with expected poor ovarian response (ePOR). Methods: We selected 115 women who entered the first in vitro fertilization (IVF) cycle between August 2013 and July 2016. The women were divided into an ePOR group (37 women) and a non-ePOR group (78 women). All women in the ePOR group were ≥ 40 years old or had serum anti-Müllerian hormone levels of less than 1.1 ng/mL at the time of the first IVF cycle. Live birth outcomes were monitored until December 2017. The cumulative LBR (with both conservative and optimistic estimates) was calculated according to the serial number of ET cycles. Results: After up to three ET cycles, the overall cumulative LBR was significantly lower in the ePOR group than in the non-ePOR group (conservative estimate, 10.8% vs. 44.9%, respectively; optimistic estimate, 14.7% vs. 56.1%, respectively; log-rank test, p= 0.003). Conclusion: Women with ePOR exhibited a lower cumulative LBR than women in the non-ePOR group, and this information should be provided to ePOR women during counseling before starting IVF.

The effects of diagnostic hysteroscopy on the reproductive outcomes of infertile women without intrauterine pathologies: a systematic review and meta-analysis

  • Yang, Soo Yeon;Chon, Seung-Joo;Lee, Seon Heui
    • Women's Health Nursing
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    • v.26 no.4
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    • pp.300-317
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    • 2020
  • Purpose: Hysteroscopy can be used both to diagnose and to treat intrauterine pathologies. It is well known that hysteroscopy helps to improve reproductive outcomes by treating intrauterine pathologies. However, it is uncertain whether hysteroscopy is helpful in the absence of intrauterine pathologies. This study aimed to confirm whether hysteroscopy improves the reproductive outcomes of infertile women without intrauterine pathologies. Methods: We conducted a systematic review of 11 studies retrieved from Ovid-MEDLINE, Ovid-Embase, and the Cochrane Library. Two independent investigators extracted the data and used risk-of-bias tools (RoB 2.0 and ROBINS-I) to assess their quality. Results: Diagnostic hysteroscopy prior to in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) was associated with a higher clinical pregnancy rate (CPR) and live birth rate (LBR) than non-hysteroscopy in patients with recurrent implantation failure (RIF) (odds ratio, 1.79 and 1.46; 95% confidence interval, 1.40-2.30 and 1.08-1.97 for CPR and LBR, respectively) while hysteroscopy prior to first IVF was ineffective. The overall meta-analysis of LBR showed statistically significant findings for RIF, but a subgroup analysis showed effects only in prospective cohorts (odds ratio, 1.40 and 1.47; 95% confidence interval, 0.62-3.16 and 1.04-2.07 for randomized controlled trials and prospective cohorts, respectively). Therefore, the LBR should be interpreted carefully and further research is needed. Conclusion: Although further research is warranted, hysteroscopy may be considered as a diagnostic and treatment option for infertile women who have experienced RIF regardless of intrauterine pathologies. This finding enables nurses to educate and support infertile women with RIF prior to IVF/ICSI.

End-to-end Reliable Message Transmission Considering Load Balancing in Wireless Networks

  • Tran, Anh Tai;Kim, Myung Kyun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.9
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    • pp.3094-3109
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    • 2014
  • This paper proposes a load balanced reliable routing protocol called LBR (Load Balanced Reliable routing) in wireless networks. The LBR protocol transmits messages through a reliable path considering the balancing of the traffic load. Recently, the authors have proposed a multipath-based reliable routing protocol called MRFR, which is an appealing protocol for fault tolerant reliable data transmission. However, However, MRFR has no concern with the problem of load balancing, which results in increasing congestion and consuming high energy at some network nodes. As a result, the problem affects negatively the performance of the network. Taking account of load balancing as a route selection criteria can avoid routing through the congested nodes and allows to find better routes. In this paper, we extend MRFR by considering load balancing in the route discovery process of reliable communication. The simulation results showed that the proposed protocol outperforms AODV in terms of end-to-end delay, packet delivery radio, and average jitter. Compared to MRFR, the LBR protocol has the same packet delivery ratio, and obtains a better efficiency of load balancing.

Effect of Selected Inoculant Applications on Chemical Compositions and Fermentation Characteristics of High Moisture Rye Silage

  • Lee, Seong Shin;Jeong, Seung Min;Seo, Myeong Ji;Joo, Young Ho;Paradhipta, Dimas Hand Vidya;Seong, Pil Nam;Kim, Sam Churl
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.42 no.3
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    • pp.155-161
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    • 2022
  • The aim of this study was to investigate the effect of isolated lactic acid bacteria (LAB) on the quality of high moisture rye silage. Rye forage (Secale cereale L.) was harvested at the heading stage (27.3% of dry matter (DM)) and cut into approximately 3-5 cm lengths. Then, the forage divided into 4 treatments with different inoculants: 1) No additives (CON); 2) Lactobacillus brevis strain 100D8 at a 1.2 × 105 colony-forming unit (cfu)/g of fresh forage (LBR); 3) Leuconostoc holzapfelii strain 5H4 at a 1.0 × 105 cfu/g of fresh forage (LHO); and 4) Mixture of LBR and LHO (1:1 ratio) applied at a 1.0 × 105 cfu/g of fresh forage (MIX). About 3 kg of forage from each treatment was ensiled into a 20 L mini-bucket silo in quadruplicate for 100 days. After silo opening, silage was collected for analyses of chemical compositions, in vitro nutrient digestibilities, fermentation characteristics, and microbial enumerations. The CON silage had the highest concentrations of neutral detergent fiber and acid detergent fiber (p = 0.006; p = 0.008) and a lowest in vitro DM digestibility (p < 0.001). The pH was highest in CON silage, while lowest in LBR and MIX silages (p < 0.001). The concentrations of ammonia-N, lactate, and acetate were highest in LBR silage (p = 0.008; p < 0.001; p < 0.001). Propionate and butyrate concentrations were highest in CON silage (p = 0.004; p < 0.001). The LAB and yeast counts were higher in CON and LHO silages compare to LBR and MIX silages (p < 0.001). However, the mold did not detect in all treatments. Therefore, this study could conclude that L. brevis 100D8 and Leu. holzapfelii strain 5H4 can improve the digestibility and anti-fungal activity of high moisture rye silage.

The Modification of Epoxy Resins with Liquid Rubbers (Liquid Rubber를 이용한 Epoxy Resin의 개질)

  • Choi, Sei-Young;Kim, Young-Jun;Yun, Ju-Ho
    • Elastomers and Composites
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    • v.31 no.1
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    • pp.13-22
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    • 1996
  • In order to Improve the fracture toughness of epoxy resin system, liquid chloroprene rubber(LCR) and liquid butadiene rubber (LBR) which have hydroxy group were used in the brittle epoxy system. Mechanical and toughness characterization of the modified epoxy resins were investigated as a function of liquid rubbers content. Epoxy resins modified with both of the liquid rubbers showed complete phase-separation microstructure : In all of the LCR content, it was observed that the domain size of LCR dispersed in the epoxy matrix ranging from $2{\mu}m\;to\;5{\mu}m$. It was found that fracture toughness, $K_{ic}$, of the modified LCR system was enhanced continuously as increasing LCR content. However around 10phr of LBR system showed maximum fracture toughness. Specifically, when BPA add to the modified LCR system, thermal and mechanical properties increased than neat epoxy. At the same time, fracture toughness was enhanced.

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Analysis of the Result of Korean Medicine Treatment for Female Subfertility Using Herbal Medicine, Acupuncture and Moxibustion Treatment

  • Jeong, Jae-Cheol;Choi, Min-Sun;Yoon, Sang-Ho;Kim, Dong-Il
    • The Journal of Korean Medicine
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    • v.36 no.2
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    • pp.1-7
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    • 2015
  • Objectives: To report on the result of infertility treatment with Korean medicine in clinical settings. Methods: This study was single arm, retrospective observational study. Analysis of the medical records on thirty four infertile women who were treated by acupuncture, moxibustion, herbal medicine(Jokyungjongoktang-gagambang, Sutaehwan-gagambang). Pregnancy rate(PR) and Live birth rate(LBR) were analyzed as the primary outcomes. Changes of AMH, FSH, LH, $E_2$, $P_4$, endometrial thickness, fat mass, and BMI were also analyzed as the secondary outcomes. Results: A total of 34 patients were treated in the traditional Korean medical clinic. Nine patients were dropped, and 25 subjects completed the final examination at the end of this treatment schedule. Five of 25 subjects conceived during treatment, reaching 20% PR and LBR was also 20%. Except for FSH level, the results of the remaining outcome measures, including LFT, showed no significant changes. No serious adverse event has been reported. Conclusion: Although no significant changes in bio-markers were observed, complex treatment using Korean medicine has shown effectiveness on women's infertility. In addition, the safety of the treatment has been verified.

The pregnancy outcomes of day-5 poor-quality and day-6 high-quality blastocysts in single blastocyst transfer cycles

  • Guang-li Zhang;Tian-yi Sun;Sen Li;Man-xi Jiang;Lei Guo
    • Clinical and Experimental Reproductive Medicine
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    • v.50 no.1
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    • pp.63-68
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    • 2023
  • Objective: This study compared the outcomes of single blastocyst transfer cycles, using day- 5 poor-quality blastocysts and day-6 high-quality blastocysts. Methods: We analyzed 462 frozen-thawed embryo transfer (FET) cycles performed at our center from January 2014 to December 2019. The cycles were divided into two groups: a day-5 poor-quality blastocyst transfer group (group A) and a day-6 high-quality blastocyst transfer group (group B). The clinical outcomes were tested. Results: In groups A and B, respectively, the clinical pregnancy rate (CPR; 61.65% vs. 67.17%, p=0.258), implantation rate (IR; 61.65% vs. 67.17%, p=0.258), and live birth rate (LBR; 69.51% vs. 77.83%, p=0.134) showed no significant differences. Moreover, when day-3 embryo quality was considered, the CPR, IR, and LBR were also similar in group A and group B (p>0.05). Conclusion: The clinical outcomes of day-5 poor-quality blastocysts and day-6 high-quality blastocysts were similar, suggesting that the developmental speed of the embryo might be more important than embryo quality for the clinical outcomes of single blastocyst transfer in FET cycles.

Comparison of assisted reproductive technology outcomes in infertile women with polycystic ovary syndrome: In vitro maturation, GnRH agonist, and GnRH antagonist cycles

  • Choi, Min Hye;Lee, Sun Hee;Kim, Hye Ok;Cha, Sun Hwa;Kim, Jin Young;Yang, Kwang Moon;Song, In Ok;Koong, Mi Kyoung;Kang, Inn Soo;Park, Chan Woo
    • Clinical and Experimental Reproductive Medicine
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    • v.39 no.4
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    • pp.166-171
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    • 2012
  • Objective: We compared the assisted reproductive technology (ART) outcomes among infertile women with polycystic ovary syndrome (PCOS) treated with IVM, conventional IVF, GnRH agonist, and GnRH antagonist cycles. Methods: The prospective study included a total of 67 cycles in 61 infertile women with PCOS. The women with PCOS were randomized into three IVF protocols: IVM/IVF with FSH and hCG priming with immature oocyte retrieval 38 hours later (group A, 14 cycles), GnRH agonist long protocol (group B, 14 cycles), and GnRH antagonist multi-dose flexible protocol (group C, 39 cycles). IVF outcomes, such as clinical pregnancy rate (CPR), implantation rate (IR), miscarriage rate (MR), and live birth rate (LBR), were compared among the three groups. Results: Age, BMI, and basal FSH and LH levels did not differ among the three groups. The number of retrieved oocytes and 2 pronucleus embryos was significantly lower in group A compared with groups B and C. The CPR, IR, MR, and LBR per embryo transfer showed no differences among the three groups. There was no incidence of ovarian hyperstimulation syndrome in group A. Conclusion: The IR, MR, and LBR in the IVM cycles were comparable to those of the GnRH agonist and GnRH antagonist cycles. The IVM protocol, FSH and hCG priming with oocyte retrieval 38 hours later, is an effective ART option that is comparable with conventional IVF for infertile women with PCOS.