• International Journal of Contents
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• v.18 no.1
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• pp.76-84
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• 2022

Tidal power generation plays a critical role in reducing greenhouse gas emissions. It uses a tidal force generated by gravitational force between the moon, the earth, and the sun. The change of seawater height generates the tide-generating force, and the magnitude of the change is the tide level. The tide level change has the same period as the tide-generating force twice a day, every 29.5 days, every year, and every 18.6 years. Sihwa Lake Tidal Power Station is Korea's first tidal power plant that began commercial power generation in August 2011 and has been accumulating a large volume of data on electricity production, power generation sales, sluice displacement, and tide levels. The purpose of this paper was to analyze the impact of the inefficiency factors affecting production and the tidal level change on tidal power generation and their characteristics using Sihwa Lake Tidal Power's operational performance data. Throughout this paper we show that tidal power generating operation is accurately predicting the trends of magnitude of tidal force to be periodical for each day. determining the drop to initiate the water turbine generator factoring the constraints on the operation of Sihwa Lake, and reflecting the water discharge through the floodgate and water turbine during the standby mode in the power generation plan to be in the optimal condition until the initiation of the next power generation can maximize power generation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.19 no.1
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• pp.33-39
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• 1983

Tidal exchange of sea water was studied by using drogue experiments and tidal current measurement data in Yeoja Bay which has a narrow channel. At the spring tide, the volume of tidal transport in the bay was estimated to be 43% of the mean volume of the sea water in Yeoja Bay, 1.96km super(3). Residual current was deduced to flow southward at the rate of 3,658$\times$10 super(4) m super(3) per tidal cycle. The mean tidal exchange of sea water during the flood flow was estimated to be approximately 5.0% of the volume of sea water at the mean high water level in the bay, 2.33km super(3), while that during the ebb flow was 6.3%. One dimensional diffusion coefficient of 1.69-1.97$\times$10 super(6) cm super(2)/sec was obtained at the channel in the bay.

• Fire Science and Engineering
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• v.28 no.6
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• pp.76-81
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• 2014

The purpose of this study was to comparative analysis of tidal volume and airway pressure after one-rescuer BVM, two-rescuer BVM, advanced airway devices with a Bag-valve mask using RespiTrainer. The data were obtained from June 2 to 10 in 2014. The collected data were analyzed using the SPSS WIN 18.0 program. The results showed that BVM ventilation using the endotracheal intubation produced higher mean tidal volume $497{\pm}78mL$, Two-rescuer ventilation $479{\pm}91mL$ One-rescuer ventilation $386{\pm}59mL$, King LTS-D $365{\pm}05mL$, Laryngeal mask airway (LMA) $351{\pm}35mL$. Peak airway pressure was higher in BVM ventilation using the endotracheal intubation. As a result, the study confirmed that the BVM Ventilation by endotracheal intubation and Two-rescuer BVM ventilation to one third the bag depth squeeze method is appropriate.

• Journal of Ocean Engineering and Technology
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• v.19 no.1 s.62
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• pp.1-7
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• 2005

Tidal circulation in a closed bay using a variation of bottom roughness was investigated through the numerical experiments based on a finite difference multi-level model. Various distributions of bottom roughness in the bay were implemented to determine their effects. It hadbeen determined that residual currents can be generated from the differences of the bottom roughness between streaming and reverse flow directions. The magnitude of residual currents and volume flow rate increase when the relative ratio of bottom roughness between streaming and reverse flow directions increase. Circulation in the closed bay is also improved by the employment of the change of bottom roughness.

• Journal of the Korea Society of Computer and Information
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• v.29 no.3
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• pp.165-171
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• 2024

This study aims to investigate the appropriate volume of artificial ventilation and success rate when Basic - emergency medical Technician administer bag valve mask(BVM) artificial ventilation to patients experiencing respiratory failure or respiratory arrest using a respiratory rate measurement device. The research was conducted from December 11th to 12th, 2023, targeting 20 Basic - emergency medical Technicians enrolled at D University. Ten participants were selected for the experimental group, receiving BVM ventilation training with the use of a respiratory rate measurement device, while the other ten were assigned to the control group, receiving BVM ventilation training without the use of a respiratory rate measurement device. The experiment involved providing artificial ventilation for 2 minutes. The results of the study indicated that the control group did not provide accurate tidal volume (p=.025). The experimental group demonstrated a higher success rate of ventilation over the 2-minute period, while the control group showed a significant difference (p=.001). Subjective perception of tidal volume and objectively measured tidal volume also exhibited a significant difference in the control group (p=.010). Therefore, training with a respiratory rate measurement device can align the subjective perception of tidal volume with objective measurements, increase the success rate of ventilation, and potentially contribute to improving survival rates in patients experiencing respiratory failure or respiratory arrest during cardiopulmonary resuscitation.

• Journal of Korean Academy of Nursing
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• v.44 no.2
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• pp.149-158
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• 2014

Purpose: This study was conducted to compare effects of open and closed suctioning methods on lung dynamics (dynamic compliance, tidal volume, and airway resistance) and hypoxemia (oxygen saturation and heart rate) in mechanically ventilated patients. Methods: This study was a cross-over repeated design. Participants were 21 adult patients being treated with endotracheal intubation using a pressure-controlled ventilator below Fraction of Inspired Oxygen ($FiO_2$) 60% and PEEP $8cmH_2O$. Data were collected at baseline and 1, 2, 3, 4, 5, and 10 minutes after suctioning. Data were analyzed using two-factor ANOVA with repeated measures on time and suctioning type. Results: Effects of the interaction between suction type and time were significant for oxygen saturation and heart rate but not significant for dynamic compliance, tidal volume, or airway resistance. Prior to performance of suctioning, tidal volume and oxygen saturation were significantly lower, but airway pressure and heart rate were significantly higher using the closed suctioning method as compared with the open suctioning method. Conclusion: For patients on ventilator therapy below $FiO_2$ 60% and PEEP $8cmH_2O$, open suctioning performed after delivery of 100% $FiO_2$ using a mechanical ventilator may not have as much negative impact on lung dynamics and hypoxemia as closed suctioning.

• Journal of Acupuncture Research
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• v.32 no.4
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• pp.195-201
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• 2015

Objectives : The purpose of this study is to report on the improvement of respiratory function of a fascioscapulohumeral muscular dystrophy patient after receiving Korean medical treatment. Methods : This study was carried out on a 60 year-old male patient who suffered from fascioscapulohumeral muscular dystrophy. While we carried out Korean medical treatment, we observed $EtCO_2$ (end-tidal carbon dioxide), Vte (exhaled tidal volume) and PIP (peak inspiratory pressure). Results : $EtCO_2$ count decreased from 34 mmHg to 24 mmHg during the treatment period, and PIP count became stable. Vte count also did not worsen in this study. Conclusions : Based on this study, we concluded that Korean medical treatment could be effective in treating fascioscapulohumeral muscular dystrophy patients with respiratory failure.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2271-2276
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• 2015

A superconducting synchronous generator (SCSG) can be expected to decrease the size and weight compared to conventional tidal current generators. This paper proposes an optimal design of a 2 MW class SCSG for a tidal current power generation system. The proposed optimal design of the SCSG will reduce the length of the high-temperature superconducting wire as well as the weight and volume of the SCSG. The 3D finite element method is used to analyze the magnetic field distribution. The optimized 2 MW SCSG is compared with a 2 MW conventional generator. As the optimized SCSG is more compact and lighter than a conventional generator, it will be efficiently applied to practical tidal power systems.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.74-79
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• 2006

General formula are presented for the maximum power available from the tidal head in a closed basin and from the tidal currents in a channel connecting two large bodies of water. In the latter case, the available energy cannot be estimated from the kinetic energy flux in the undisturbed state, but can be obtained from knowledge of the tidal head between the ends of the channel and the maximum volume flux in the undisturbed state. The results are supported by detailed calculations for Johnstone Strait, British Columbia, using a two-dimensional finite element model. The model also allows an extension to the case of multiple channels. More work is needed to allow for partial tidal fences which do not occupy the whole cross-section of a channel.

• Ocean and Polar Research
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• v.38 no.4
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• pp.315-324
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• 2016

In this study, we investigated changes in the macrobenthic community in Sihwa tidal flat before and after the operation of a Tidal Power Plant (TPP). In order to investigate changes in the macrobenthic community structure, field surveys were conducted at eighteen stations in 4 transect lines every September from 2011 to 2015. Mean density of macrobenthos decreased to $116ind./m^2$ in 2015 from $1,602ind./m^2$ in 2011. While the mean density of macrobenthos has decreased, species richness and biomass have gradually increased. The species diversity and SEP (Shannon-wiener Evenness Proportion) have also gradually increased over time since the operation of the TPP. The macrobenthic community in Sihwa tidal flat was divided into 4 groups on a yearly base. Before the operation of TPP, opportunistic species such as Neanthes succina and Polydora cornuta largely contributed to the structure of the macrobenthic community, while equilibrium species such as Periserrula leucophryna and Scopimera globosa contributed after the operation. With the operation of TPP, the macrobenthic community has rapidly recovered and this might be related to improvement in the quality of water and sedimentary environments as a result of an increase in water mass volume exchanged through the TPP gate.