• Title/Summary/Keyword: Anti-reduction System

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Development of Low-Cost Automatic Flight Control System for an Unmanned Target Drone (무인표적기용 저가형 자동비행시스템 개발)

  • Lee, Jang-Ho;Ryu, Hyeok;Kim, Jae-Eun;Ahn, Iee-Ki
    • Journal of Advanced Navigation Technology
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    • v.8 no.1
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    • pp.19-26
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    • 2004
  • This paper deals with the automatic flight control system for an unmanned target drone which is operated by an army as an anti-air gun shooting training. By automation of unmanned target drone that is manually operated by external pilot, pilot can reduce workload and an army can reduce the budget. Most UAVs which are developed until today use high-cost sensors as AHRS and IMU to measure the attitude, but those are contradictory for the reduction of budget. This paper says the development of low-cost automatic flight control system which makes possible of automatic flight with low-cost sensors. We have developed the integrated automatic flight control system by integrating electricity module, switching module, monitoring module and RC receiver as an one module. We also prove the performance of automatic flight control system by flight test.

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Effects of Rehmanniae Radix on HPA Axis System and Catecholamienrgic System in FST (생지황(生地黃)이 강제수영부하시험에서 HPA Axis System과 Catecholaminergic System에 미치는 영향)

  • Park, Jae-Beom;Lee, Tae-Hee
    • Herbal Formula Science
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    • v.18 no.1
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    • pp.133-144
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    • 2010
  • Object : The effects of Rehmanniae Radix(RR) on HPA Axis system and Catecholaminergic system was investigated. Methods : we performed the Forced Swimming Test(FST). Also the expression of Corticotropin -Releasing Factor(CRF), c-Fos and Tyrosine Hydorxylase(TH) was measured by immunohistochemical method at Paraventricular Nucleus(PVN), Locus Coeruleus(LC) and Ventral Tegmental Area(VTA). Results : 1. The duration of immobility in the Forced Swimming Test was significantly decreased in the Rehmanniae Radix 400 mg/kg groups in comparison with the control group(p<0.05). 2. Comparing to the control group, CRF expression was significantly decreased in the Rehmanniae Radix 400 mg/kg treated group in comparison with the control group(p<0.01). 3. c-Fos expression was significantly decreased at PVN in the Rehmanniae Radix 100 mg/kg treated group in comparison with the control group(p<0.01). 4. TH expression was significantly increased at LC in the Rehmanniae Radix 100 mg/kg and 400 mg/kg treated group in comparison with the control group(p<0.001). 5. TH expression was significantly decreased at VTA in the Rehmanniae Radix 100 mg/kg and 400 mg/kg treated group in comparison with the control group(p<0.001). Conclusion : According to the results, it can be considered that Rehmanniae Radix has antidepressant effect by showing the reduction of immobility in FST through the decreased expression of CRF, c-Fos in PVN and TH in VTA.

Antioxidant and Free Radical Scavenging Potential of Justicia gendarussa Burm. Leaves in vitro.

  • Mruthunjaya, K.;Hukkeri, V.I.
    • Natural Product Sciences
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    • v.13 no.3
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    • pp.199-206
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    • 2007
  • Antioxidant activity of 70% aqueous ethanolic extract of leaves of Justicia gendarussa (EJ) was evaluated. EJ was prepared by cold maceration method. The antioxidant potency of EJ was investigated employing various established in vitro systems, such as DPPH radical scavenging, nitric oxide (NO) scavenging, ${\beta}-carotene$ linoleic acid module system (${\beta}$ CLAMS), hydroxyl (OH) radical scavenging, anti lipid peroxidation. $IC_{50}$ values were determined in each experiment. Also, ferric ion reduction capacity of extracts in presence and absence of chelating agent (EDTA) and total antioxidant capacity were determined. Preliminary phytochemical investigation was carried out to know the nature of constituents present in the leaves and correlate it with antioxidant activity. Further total phenolic content was determined in EJ. $IC_{50}$ values of EJ were 123.09 ${\pm}$ 3.01, 643.0 ${\pm}$ 61.10, 132.3 ${\pm}$ 6.03, 68.5 ${\pm}$ 11.5 and 68.13 ${\pm}$ 1.38 ${\mu}g/mL$ in DPPH radical scavenging, NO scavenging, ${\beta}$ CLAMS, OH radical scavenging and anti lipid peroxidation activity respectively. In total antioxidant capacity assay, ascorbic acid equivalent value was found to be 205.56 ${\pm}$ 4.69 ${\mu}g/mg$ of extract. Total phenolic content was found to be 43.76 ${\pm}$ 4.27 ${\mu}g$ equivalent of gallic acid per mg of extract. Phytochemical investigation reveals the presence of flavonoids. The results indicate that EJ possess antioxidant activity and flavonoids are responsible for this activity.

New evidence on mechanisms of action of spa therapy in rheumatic diseases

  • Tenti, Sara;Fioravanti, Antonella;Guidelli, Giacomo Maria;Pascarelli, Nicola Antonio;Cheleschi, Sara
    • CELLMED
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    • v.4 no.1
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    • pp.3.1-3.8
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    • 2014
  • Spa represents a treatment widely used in many rheumatic diseases (RD). The mechanisms by which immersion in mineral or thermal water ameliorates RD are not fully understood. The net benefit is probably the result of a combination of factors, among which the mechanical, thermal and chemical effects are most prominent. Buoyancy, immersion, resistance and temperature play important roles. According to the gate theory, pain relief may be due to the pressure and temperature of the water on skin; heat may reduce muscle spasm and increase the pain threshold. Mud-bath therapy increases plasma ${\beta}$-endorphin levels and secretion of corticotrophin, cortisol, growth hormone and prolactin. It has recently been demonstrated that thermal mud-bath therapy induces a reduction in circulating levels of prostaglandin E2, leukotriene B4, interleukin-$1{\beta}$ and tumour necrosis factor-${\alpha}$, important mediators of inflammation and pain. Furthermore, balneotherapy has been found to cause an increase in insulin-like growth factor-1, which stimulates cartilage metabolism, and transforming growth factor-${\beta}$. Beneficial anti-inflammatory and anti-degenerative effects of mineral water were confirmed in chondrocytes cultures, too. Various studies in vitro and in humans have highlighted the positive action of mud-packs and thermal baths, especially sulphurous ones, on the oxidant/antioxidant system. Overall, thermal stress has an immunosuppressive effect. Many other non-specific factors may also contribute to the beneficial effects observed after spa therapy in some RD, including effects on cardiovascular risk factors (e.g. adipokines) and changes in the environment, pleasant surroundings and the absence of work duties.

A Study on the Anti-Rolling Systems for Vessels (선박용 감요장치에 대한 고찰)

  • Kwon, Sun-Young;Hong, Bong-Ki
    • Journal of Fisheries and Marine Sciences Education
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    • v.9 no.2
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    • pp.167-178
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    • 1997
  • It has been expected not only for crew but also for passengers to realize a ship whose rolling and other motions are small as much as possible. Restricting our consideration to the roll reduction, the conventional roll stabilization system, fins or anti-rolling tanks hve been utiized as the actuator. Excessive motions would interfere with the recreational activities of passengers on a cruise ship. Often more than half of the load of a containership is stowed above deck where it is subjected to large acclerations due to rolling. In some situations this may cause some internal damage to the contents of the containers; in more severe situations failure of the lashing can occur and containers may be lost over-board. Underdeck cargo in ordinary cargo ships and bulk commodities in colliers, ore ships and grain ships can shift if the motions become too severe. The purpose of this study is to concentrate on the additions. either internal or external to the hull, that reduce or otherwise improve the motion responses of the hull. It is assumed that the additions are such that their benefit to the motions of the ship outweights any impact on the ability of the ship to perform its assigned task. It is particularly challenging to obtain large improvements in the motion characteristics of existing ships that are being rebuilt or modified for some task not anticipated in their original design. Further the authors will statistically analyze the influence of ruder-roll-yaw coupling motion in the case of application of this advanced control method to various kinds of ship.

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Development and Application of Dry Process Caisson for Maintenance of Submerged Barber Structure

  • Lee, Joong-Woo;Lee, Seung-Chul;Oh, Dong-Hoon;Kwak, Seung-Kyu;Lee, Jeong-Su
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.10a
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    • pp.105-114
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    • 2006
  • Together with the trend of enhancement in domestic industrial development and economic progress due to import and export, the demand for construction of the roads, bridges, especially port facilities, and several coastal protection and ocean structures is increasing rapidly. MOMAF of Korean Government is driving construction of 9 new ports and renovation of the existing fishery ports. Among these structures most of bridge base, wharves, dolphins, quays, and jetties are being newly built of steel or concrete pile. As the base, supporting bulkheads, and piles are underwater after construction, it is difficult to figure out the status of structures and not enough to get maintenance and strengthen the structures. Every year, moreover, these works suck the government budget due to higher incomplete maintenance expense for protection from corrosions of structures and increased underwater construction period. for the purpose of cutting down the government budget, it is necessary to extend the life cycle of the existing structures. We developed a new method for maintenance of submerged structures near the waterline by allowing dry work environment with the floating caisson. The method shows easy to move around the working area and handle. It also showed not only a significant reduction of maintenance expenses and time for anti-corrosion work but also better protection. This will be a milestone to reduce the maintenance and construction expenses for the shore and water structures.

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Performance Analysis of Mode Switching Scheme for Reduction of Phase Distortion in GPS Anti-jamming Equipment Based on STAP Algorithm

  • Jung, Junwoo;Yang, Gi-Jung;Park, Sungyeol;Kang, Haengik;Kwon, Seungbok;Kim, Kap Jin
    • Journal of Positioning, Navigation, and Timing
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    • v.8 no.3
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    • pp.95-105
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    • 2019
  • A method that applies space-time adaptive signal processing (STAP) algorithm based on an array antenna consisting of multiple antenna elements has been known to be effective to remove wide-band jamming signals in GPS receivers. However, the occurrence of phase distortion in navigation signals has been a problem when navigation signals, from which jamming signals are removed using STAP, are supplied to global positioning system (GPS) receivers. This paper verified the navigation performance degradation as a result of phase distortion. To mitigate this phenomenon, this paper proposes a mode switching scheme, in which a bypass mode is adopted to make the best use of the tracking performance of receivers without performing signal processing when jamming signals are not present or weak, and a STAP mode is employed when jamming signals exceed the threshold value. In this paper, the mode switching scheme is proposed for two environments: when receivers are stationary, and when receivers are moving. This paper confirmed that the performance of position error improved because phase distortion could be excluded due to STAP if the bypass mode was adopted under a condition where the jamming signal power level was below the threshold value in an environment where receivers were stationary. However, this paper also observed that the navigation failed due to the instability of tracking performance of receivers due to phase distortion that occurred at the switching time, although the number of switching could be reduced dramatically by proposing a dual threshold scheme of on- and off-thresholds that switched a mode due to the array antenna characteristics of varying gains according to the jamming signal incident direction in an environment where receivers were moving. The analysis results verified that running the STAP algorithm at all times is more efficient than the mode switching, in terms of maintaining stable navigation and ensuring position error performance, to remove jamming signals in an environment where receivers were moving.

A Review of the Health Benefits of Kimchi Functional Compounds and Metabolites

  • Hyun Ju Kim;Min Sung Kwon;Hyelyeon Hwang;Ha-Sun Choi;WooJe Lee;Sang-Pil Choi;Haeun Jo;Sung Wook Hong
    • Microbiology and Biotechnology Letters
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    • v.51 no.4
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    • pp.353-373
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    • 2023
  • Kimchi is a traditional Korean dish made with salted fermented vegetables and contains various nutrients and functional substances with potential health benefits. The fermentation process used to make kimchi creates chemical changes in the food, developing nutrients and functional substances that are more easily absorbed and enhanced by the body. Recent studies have shown that several lactic acid bacteria strains isolated from kimchi exhibit probiotic properties and have several health benefiting properties such as such as anticancer, anti-obesity, and anti-constipation; they also promote colon health and cholesterol reduction in in vitro and in vivo experiments, as well as in epidemiological cohort studies. Kimchi contains prebiotics, non-digestible fibers that nourish beneficial gut bacteria; therefore, its intake effectively provides both probiotics and prebiotics for improved gut health and a fortified gut-derived immune system. Furthermore, fermentation of kimchi produces a variety of metabolites that enhance its functionality. These metabolites include organic acids, enzymes, vitamins, bioactive compounds, bacteriocins, exopolysaccharides, and γ-aminobutyric acid. These diverse health-promoting metabolites are not readily obtainable from single food sources, positioning kimchi as a valuable dietary option for acquiring these essential components. In this review, the health functionalities of kimchi ingredients, lactic acid bacteria strains, and health-promoting metabolites from kimchi are discussed for their properties and roles in kimchi fermentation. In conclusion, consuming kimchi can be beneficial for health. We highlight the benefits of kimchi consumption and establish a rationale for including kimchi in a balanced, healthy diet.

Impact of High-Dose Statin Pretreatment in Patients with Stable Angina during Off-Pump Coronary Artery Bypass

  • Youn, Young-Nam;Park, Seong-Yong;Hwang, Yoo-Hwa;Joo, Huyn-Chul;Yoo, Kyung-Jong
    • Journal of Chest Surgery
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    • v.44 no.3
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    • pp.208-214
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    • 2011
  • Background: Periprocedural treatment with high-dose statins is known to have cardioprotective and pleiotropic effects, such as anti-thrombotic and anti-inflammatory actions. We aimed to assess the efficacy of high-dose rosuvastatin loading in patients with stable angina undergoing off-pump coronary artery bypass grafting (OPCAB). Materials and Methods: A total of 142 patients with stable angina who were scheduled to undergo surgical myocardial revascularization were randomized to receive either pre-treatment with 60-mg rosuvastatin (rosuvastatin group, n=71) or no pre-treatment (control group, n=71) before OPCAB. The primary endpoint was the 30-day incidence of major adverse cardiac events (MACEs). The secondary endpoint was the change in the degree of myocardial ischemia as evaluated with creatine kinase-myocardial band (CK-MB) and troponin T (TnT). Results: There were no significant intergroup differences in preoperative risk factors or operative strategy. MACEs within 30 days after OPCAB occurred in one patient (1.4%) in the rosuvastatin group and four patients (5.6%) in the control group, respectively (p=0.37). Preoperative CK-MB and TnT were not different between the groups. After OPCAB, the mean maximum CK-MB was significantly higher in the control group (rosuvastatin group $10.7{\pm}9.75$ ng/mL, control group $14.6{\pm}12.9$ ng/mL, p=0.04). Furthermore, the mean levels of maximum TnT were significantly higher in the control group (rosuvastatin group $0.18{\pm}0.16$ ng/mL, control group $0.39{\pm}0.70$ ng/mL, p=0.02). Conclusion: Our findings suggest that high-dose rosuvastatin loading before OPCAB surgery did not result in a significant reduction of 30-day MACEs. However, high-dose rosuvastatin reduced myocardial ischemia after OPCAB.

On Vortex Reduction Characteristics of Pump Sump Circulating Water Intake Basin of Power Plant Using Hydraulic Experiment (수리실험을 이용한 발전소의 순환수 취수부 흡입수조의 와류저감에 관한 연구)

  • Eom, Junghyun;Lee, Du Han;Kim, Hung Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.6
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    • pp.815-824
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    • 2022
  • Among the main facilities of the power plant, the circulating water used for cooling the power generation system is supplied through the Circulation Water Intake Basin (CWIB). The vortexes of various types generated in the Pump Sump (PS) of CWIB adversely affect the Circulation Water Pump (CWP) and pipelines. In particular, the free surface vortex accompanied by air intake brings about vibration, noise, cavitation etc. and these are the causes of degradation of CWP performance, damage to pipelines. Then power generation is interrupted by the causes. Therefore, it is necessary to investigate the hydraulic characteristics of CWIB through the hydraulic model experiment and apply an appropriate Anti Vortex Device (AVD) that can control the vortex to enable smooth operation of the power plant. In general, free surface vortex is controlled by Curtain Wall (CW) and the submerged vortex is by the anti vortex device of the curtain wall. The detailed specifications are described in the American National Standard for Pump Intake Design. In this study, the circulating water intake part of the Tripoli West 4×350 MW power plant in Libya was targeted, the actual operating conditions were applied, and the vortex reduction effect of the anti vortex device generated in the suction tank among the circulating water intake part was analyzed through a hydraulic model experiment. In addition, a floor splitter was basically applied to control the submerged vortex, and a new type of column curtain wall was additionally applied to control the vortex generated on the free surface to confirm the effect. As a result of analyzing the hydraulic characteristics by additionally applying the newly developed Column Curtain Wall (CCW) to the existing curtain wall, we have found that the vortex was controlled by forming a uniform flow. In addition, the vortex angle generated in the circulating water pump pipeline was 5° or less, which is the design standard of ANSI/HI 9.8, confirming the stability of the flow.