• International Journal of Computer Science & Network Security
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• 제21권9호
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• pp.113-117
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• 2021

The article defines the basic concepts: "election campaign", "social capital", "conversion of social capital"; the principles and methods of research of social capital conversion in election campaigns are studied; the process of using social capital in politics is defined; ways of converting social capital into politics are considered; the possibilities of converting social capital in election campaigns are described. Election campaigns have been found to be a successful form of social capital conversion. The ability to use social capital in the election campaign speaks of its high potential. Election campaigns are not an effective use of social capital.

• 대한한방내과학회지
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• 제21권3호
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• pp.399-407
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• 2000

This study was carried out to examine if Haejohwan (HJ) inhibits oxidant-induced lipid peroxidation and therby produces protective effect against thyroxine-induced hyperthyroid rats. Triiodothyronine $(T_3)$, thyroxine $(T_4)$, lipid peroxidation, xathine oxidase activities and type conversion ratio were increased in thyroxine treated group. However, they were decreased in HJ extract's pre-applied group. Glutathione level, activities of glutathione peroxidase, glutathione Stransferase and glutathione reductase were decreased in thyroxine treated group. But, they were increased in HJ extract's pre-applied group. These results suggest that in thyroxine-induced hyperthyroid rats HJhas an increase in the activities of oxygen free radical scavenging enzymes and inhibition of xanthine oxidase activities, and prevents lipid peroxidation.

• 방사선산업학회지
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• 제17권2호
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• pp.161-172
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• 2023

Coal-fired power plants handle large quantities of coal, one of the most prominent NORM, and the coal ash produced after the coal is burned can be tens of times more radioactive than the coal. Workers in these industries may be exposed to internal exposure by inhalation of particles while handling NORM. This study evaluated the size, concentration, particle shape and density, and radioactivity concentrations of airborne suspended particles in the main processes of a coal-fired power plant. Finally, the internal radiation dose to workers from particle inhalation was evaluated. For this purpose, airborne particles were collected by size using a multi-stage particle collector to determine the size, shape, and concentration of particles. Samples of coal and coal ash were collected to measure the density and radioactivity of particles. The dose conversion factor and annual radionuclide inhalation amount were derived based on the characteristics of the particles. Finally, the internal radiation dose due to particle inhalation was evaluated. Overall, the internal radiation dose to workers in the main processes of coalfired power plants A and B ranged from 1.47×10^-5~1.12×10^-3 mSv y^-1. Due to the effect of dust generated during loading operations, the internal radiation dose of fly ash loading processes in both coal-fired power plants A and B was higher than that of other processes. In the case of workers in the coal storage yard at power plants A and B, the characteristic values such as particle size, airborne concentration, and working time were the same, but due to the difference in radioactivity concentration and density depending on the origin of the coal, the internal radiation dose by origin was different, and the highest was found when inhaling coal imported from Australia among the five origins. In addition, the main nuclide contributing the most to the internal radiation dose from the main processes in the coal-fired power plants was thorium due to differences in dose conversion factors. However, considering the external radiation dose of workers in coal-fired power plants presented in overseas research cases, the annual effective dose of workers in the main processes of power plants A and B does not exceed 1mSv y^-1, which is the dose limit for the general public notified by the Nuclear Safety Act. The results of this study can be utilized to identify the internal exposure levels of workers in domestic coal-fired power plants and will contribute to the establishment of a data base for a differential safety management system for NORM-handling industries in the future.

• Korean Journal of Radiology
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• 제22권12호
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• pp.1974-1984
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• 2021

Objective: This study aimed to compare the efficacy between no-touch (NT) radiofrequency ablation (RFA) and conventional RFA using twin internally cooled wet (TICW) electrodes in the bipolar mode for the treatment of small hepatocellular carcinomas (HCC). Materials and Methods: In this single-center, two-arm, parallel-group, prospective randomized controlled study, we performed a 1:1 random allocation of eligible patients with HCCs to receive NT-RFA or conventional RFA between October 2016 and September 2018. The primary endpoint was the cumulative local tumor progression (LTP) rate after RFA. Secondary endpoints included technical conversion rates of NT-RFA, intrahepatic distance recurrence, extrahepatic metastasis, technical parameters, technical efficacy, and rates of complications. Cumulative LTP rates were analyzed using Kaplan-Meier analysis and the Cox proportional hazard regression model. Considering conversion cases from NT-RFA to conventional RFA, intention-to-treat and as-treated analyses were performed. Results: Enrolled patients were randomly assigned to the NT-RFA group (37 patients with 38 HCCs) or the conventional RFA group (36 patients with 38 HCCs). Among the NT-RFA group patients, conversion to conventional RFA occurred in four patients (10.8%, 4/37). According to intention-to-treat analysis, both 1- and 3-year cumulative LTP rates were 5.6%, in the NT-RFA group, and they were 11.8% and 21.3%, respectively, in the conventional RFA group (p = 0.073, log-rank). In the as-treated analysis, LTP rates at 1 year and 3 years were 0% and 0%, respectively, in the NT-RFA group sand 15.6% and 24.5%, respectively, in the conventional RFA group (p = 0.004, log-rank). In as-treated analysis using multivariable Cox regression analysis, RFA type was the only significant predictive factor for LTP (hazard ratio = 0.061 with conventional RFA as the reference, 95% confidence interval = 0.000-0.497; p = 0.004). There were no significant differences in the procedure characteristics between the two groups. No procedure-related deaths or major complications were observed. Conclusion: NT-RFA using TICW electrodes in bipolar mode demonstrated significantly lower cumulative LTP rates than conventional RFA for small HCCs, which warrants a larger study for further confirmation.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.425-427
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• 2008

Active area of dye-sensitized solar cell (DSSC) has an effect on the efficiency of DSSC. As the active area increases, the efficiency goes down in a general way. This is caused by the increase of internal resistance in DSSC. The internal resistances are related to various resistant elements. The charge transfer processes at Pt counter electrode and the sheet resistance of TCO are two of these resistant elements. In this study, we try to divide the active area into several small sections in a large sized cell to reduce these two internal resistant elements. As a result, we find out that the fill factor is increased and then the conversion efficiency is improved as the number of dividing active area into several small sections is increased.

• Ocean Systems Engineering
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• 제3권4호
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• pp.309-325
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• 2013

Ocean Thermal Energy Conversion (OTEC) systems utilize the temperature difference between the surface water and deep ocean water to generate electrical energy. In addition to ocean surface waves, wind and current, in certain locations like the Andaman Sea, Sulu Sea and the South China Sea the presence of strong internal waves may become a concern in floating OTEC system design. The current paper focuses on studying the dependence of the CWP hydrodynamic drag on relative velocity of the flow around the pipe, the effect of drag amplification due to vortex induced vibrations and the influence of internal waves on the floating semi and the cold water pipe integrated OTEC system. Two CWP sizes are modeled; the 4m diameter pipe represents a small scale prototype and the 10m diameter pipe represents a full commercial size CWP. are considered in the study.

• 대한한방내과학회지
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• 제20권1호
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• pp.111-121
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• 1999

Cervus elaphus (CE), being known to reinforce Kidney, have tested to study the effects concerning damages of renal tissue induced by oxygen free radicals. I had observed the effects of CE extract on damages of rat's kidney following ischemia and reflow. Before ischemia was caused, CE extract was applied $0.2m{\ell}$ per 250g through femoral vein in ischemia and reflow group and normal sailine was applied in normal group, Ischemia was caused by renal artery's clamp for 60 min and reflowed by clamp remove after 30 min. It was increased on the content of lipid peroxidation, activies and type conversion ratio of xanthine oxidase following ischemia and reflow. by clamp remove after 30 min. It was increased on the content of lipid peroxidation, activies and type conversion ratio of xanthine oxidase following ischemia and reflow. However, they were decreased when CE extract was pre-applied. Glutathione level was decreased in ischemia and reflow group, and increased in CE extract's pre-applied group. However, it could not seen special changes on aldehyde oxidase activities, either. In conclusion, CE extract recovers the damage of kidney due to ischemia and reflow by decreasing the lipid peroxidation.

• Journal of Digestive Cancer Research
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• 제7권2호
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• pp.61-64
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• 2019

We report two cases of patients with unresectable pancreatic cancer treated with neoadjuvant chemotherapy and surgical resection. In the first case, main mass was located at the neck of the pancreas, encasing superior mesenteric artery and peritoneal seeding was suspected. In the second case, main mass was located at the body of pancreas and superior mesenteric artery was encased. Both patients received FOLFIRINOX chemotherapy regimen, consisting of 5-FU, folinic acid, irinotecan and oxaliplatin. In both cases, tumor size decreased and vascular involvement regressed in response to chemotherapy. After subsequent chemoradiation therapy, both patients underwent surgical resection with negative resection margin. The pathological stages were ypT1cN0 and ypT1aN0, respectively. Both patients received postoperative adjuvant chemotherapy with 6 cycles of 5-FU/folinic acid and remained without evidence of disease for more than 6 months after the surgery.

• Journal of Power Electronics
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• 제5권2호
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• pp.99-103
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• 2005

In this paper, a novel circuit topology of a three-winding coupling inductor-assisting a high-frequency PWM boost chopper type DC-DC power converter with a high boost voltage conversion ratio and low switch voltage stress is proposed for the new energy interfaced DC power conditioner in solar photovoltaic and fuel cell generation systems. The operating principle in a steady state is described by using its equivalent circuits under the practical condition of energy processing of a lossless capacitive snubber. The newly-proposed power MOSFET boost chopper type DC-DC power converter with the three-winding coupled inductor type transformer and a single lossless capacitor snubber is built and tested for an output power of 500W. Utilizing the lower voltage and internal resistance power MOSFET switch in the proposed PWM boost chopper type DC-DC power converter can reduce the conduction losses of the active power switch compared to the conventional model. Therefore, the total actual power conversion efficiency under a condition of the nominal rated output power is estimated to be 81.1 ％, which is 3.7％ higher than the conventional PWM boost chopper DC power conversion circuit topology.

• 전기학회논문지
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• 제56권5호
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• pp.938-943
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• 2007

In this paper, we show that, in case of piezoelectric micropower generator, just replacing Schottky diodes in the bridge rectifier with ultra-low reverse leakage current diodes improves the mechanical-to-electrical energy conversion efficiency by more than 100%. Experimental and PSPICE simulation results show that, due to the ultra-low leakage current, the charging speed of the circuit employing PAD1 is higher than that of the circuit employing Schottky diodes and the saturation voltage of the circuit employing PAD1 is also higher. This study suggests that , when the internal impedance of source is very large (a few tens of $M{\Omega}$) such that maximum charging current is a few microamperes or less, in order to realize literally the energy scavenging system, ultra-low reverse leakage current diodes should be used for efficient energy conversion. Since low-level vibration is ubiquitous in the environment ranging from human movement to large infrastructures and the mechanical-to-electrical energy conversion efficiency is much more critical for use of these vibrations, we believe that the improvement in the efficiency using ultra-low leakage diodes, as found in this work, will widen greatly the application of piezoelectric micropower generator.