• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.349-358
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• 2024

This study conducted a literature analysis to examine the overall trend of speech-language pathology in discourse research, focusing on studies on the topic of discourse from 2010 to 2023. Twenty-five papers were selected and analyzed in terms of research status, research subjects (age and subject type), and research methods (type and task). As a result, first, looking at the annual status of discourse research, it was confirmed that it is increasing starting from 2015 compared to 2010 to 2014. Second, the age of the research subjects and the types of experimental and control groups in the experimental study were examined. First, when analyzing the age of the subjects, research was actively conducted on school-age subjects (12 studies, 48.00%). When looking at the analysis of the types of experimental group subjects, the Normal group was the most (4 studies (19.04%)), and the control group subject type was also conducted with Normal as the control group (13 studies (61.90%)). It was the most. Third, in the analysis of research methods, it was found that the research type was very biased towards experimental studies, with 21 studies (84.00%). The type of research in terms of time was cross-sectional studies, which accounted for a high proportion of 21 studies (84.00%), and the research project used to evaluate discourse ability with a high proportion was discourse production, with a total of 12 studies (48.00%). This study comprehensively looked at discourse-related research related to language development and language disorders and sought to identify recent trends and the direction in which discourse-related research should move. The analysis of this study was limited to domestic papers. In follow-up research, we hope to understand the flow of research and discuss it, including overseas research related to discourse.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.5
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• pp.435-441
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• 2024

Every year, safety regulations are strengthened and applied to ships to help prevent accidents. However, the number of accidents has not decreased. When fire breaks out on a ship, the escape time varies depending on wher the fire is, and the risk of hazardous factors increase. Study is conducted to better understand the risks associated with factors and causes of delayed escape time owing to changes in fire location, as well as to reduce the time delay. To study the flow of combustion products and the escape process during a fire on ship., fire and passenger escape simulation were conducted using Pyrosim and Pathfinder based on FDS. As the location of the fire changed, the average visibility distance of the escape route increased from 3.1 to 4.2 m. This indicates that the escape process was unsafe, as the passengers' escape time increased from 9 to 34 seconds compared to the case without fire. We conducted the same simulation randomly applying smoke control systems. The average visibility in the fire zone increases from 14.9 to 22.0 m. Depending on the installation of smoke suppression, escape times improved from 0.8 to 8.3 seconds. The implementation of safety improvements in the area, has clearly reduced the risk of combustion products to passengers by activating appropriate smoke control system.

• The Journal of Korean Medicine
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• v.29 no.4
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• pp.205-212
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• 2008

Background and purpose: So far it was reported that acupuncture increased cerebral blood supply and stimulated the functional activity of brain nerve cells. A previous study demonstrated a correlation between LI4-11 electro-acupuncture (EA) and rCBF increase in frontal lobe. However, there remained a need to study further using various controls in acupuncture research. Transcutaneous electrical nerve stimulation (TENS) has been used as a non-invasive control in acupuncture study. This study was to evaluate the effect of LI4-LI11 TENS on regional cerebral blood flow (rCBF) in normal volunteers using single photon emission computed tomography (SPECT) and statistical parametric mapping (SPM). Methods: In the resting state, $^{99m}Tc-ECD$ brain SPECT scans were performed on 10 normal volunteers (9 males, 1 female, mean age 26.6$\pm$0.5 years; age range from 26 to 27 years). On the other day, 7 days after the resting examination, 15 minute TENS were applied at LI 4 and LI 11 on the right side of the subjects. Immediately after LI4-LI11 TENS, the second SPECT images were obtained in the same manner as the resting state. Significant increases and decreases of regional cerebral blood flow after LI4-LI11 TENS were estimated by comparing their SPECT images with those of the resting state using paired t statistics at every voxel, which were analyzed by statistical parametric mapping with a threshold of p = 0.001, uncorrected (extent threshold: k=100 voxels). Results: TENS applied at right LI4-LI11 increased rCBF in the left somatosensory association cortex (Brodmann area 5, 7). However there was no area where LI4-11 TENS decreased rCBF. Conclusion and suggestions: These results demonstrate that right LI4-LI11 TENS increased rCBF only in corresponding somatosensory association cortex, which was different from the previous results using LI4-11 EA. It is suggested that there be a different mechanism between TENS and EA.

• The Korean Journal of Nuclear Medicine
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• v.34 no.3
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• pp.183-198
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• 2000

Purpose: The purpose of this study was to evaluate alterations of regional cerebral blood flow (CBF) and cerebrovascular reserve (CVR), and correlation between these alternations and cognitive dysfunction in patients with chronic traumatic brain injury (TBI) and normal brain MRI findings. Materials and Methods: Thirty TBI patients and 19 healthy volunteers underwent rest/acetazolamide brain SPECT using Tc-99m HMPAO. Korean-Wechsler Adult Intelligence scale test was also performed in the patient group. Statistical analysis was performed with statistical parametric mapping software (SPM'97) Results: CBF was diminished in the left hemisphere including Wernicke's area in all patients with lower verbal scale scores. In addition, a reduction in CBF in the right frontal, temporal and parietal cortices was related with depressed scores in information, digital span, arithmetic and similarities. In patients with lower performance scale scores, CBF was mainly diminished in the right hemisphere including superior temporal and supramarginal gyri, premotor, primary somatomotor and a part of prefrontal cortices, left frontal lobe and supramarginal gyrus. CVR was diminished in sixty-four Brodmann's areas compared to control. A reduction in CVR was demonstrated bilaterally in the frontal and temporal lobes in patients with lower scores in both verbal and performance tests, and in addition, both inferior parietal and occipital lobes in information subset. Conclusion: Alterations of CBF and CVR were demonstrated in the symptomatic TBI patients with normal MRI finding. These alterations were correlated with the change of intelligence, of which the complex functions are subserved by multiple interconnected cortical structures.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.3-9
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• 2013

Purpose: Currently commercially available phantom can reproduce and evaluate only a static situation, the study is incomplete research on phantom and system which is can confirmed functional situation in the kidney by time through dynamic phantom and blood flow velocity, various difference according to the amount of radioactive. Therefore, through this study, it has produced the dynamic kidney phantom to reproduce images through the dynamic flow of the kidney, it desire to evaluate the usefulness of nuclear medicine imaging. Materials and Methods: The production of the kidney phantom was fabricated based on the normal adult kidney, in order to reproduce the dynamic situation based on the fabricated kidney phantom, in this study it was applied the volume pump that can adjust the speed of blood flow, so it can be integrated continuously radioactive isotopes in the kidney by using $^{99m}Tc-pertechnate$. Used the radioactive isotope was supplied through the two pump. It was confirmed the changes according to the infusion rate, radioactive isotopes and the different injection speeds on the left and right, analysis of the acquired images was done by drawn ten times ROI in order to check the reproducibility of each on the front and rear of the kidney and bladder. Results: Under the same conditions infusion rate 40 mL/min fixed to adjust the pressure of the pump when the radiopharmaceuticals between 2-3 minutes in the most integrated in the kidney phantom was excreted inthe bladder. Glomerular filtration rate (GFR), respectively, by each device SYMBIA 1,091 mL/min, FORTE 1,232 mL/min, ARGUS 1,264 mL/min, INFINIA 1,302 mL/min in that there isno statistically significant difference was found, Tmax values and T1/2 values stars from all equipment with no statistically significant difference was found. CV values of the coefficient of variation less than 5% was found to be repeatable, and to 2.67% of the lowest SYMBIA appeared, INFINIA was the highest in the 4.86%. Conclusion: Through this study, the results showed that the dynamic kidney phantom system is able to similarly reproduce renogram in the actual clinical. Especially, the depicted over time for the flow to be excreted through the kidney into the bladder was adequately reproduce, it is expected to be utilized as basic data to check the quality of the dynamic images. In addition, it is considered to help in the field of functional imaging and quality control.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.291-298
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• 2018

Purpose: The purpose of this study was to identify the effects of Problem-Based Learning on Academic Resilience, Learning Flow, and Academic Motivation in nursing students. Methods: Research design was a non-equivalent control group pretest-posttest design. The participants were 121 sophomore nursing students from two universities. They were divided into the Problem-Based Learning group (n=61) and Lecture-Based Learning group (n=60). The data were analyzed by Chi-square, paired t-test, and independent t-test. Results: In the PBL group, there was statistically significant improvement in Academic Resilience after intervention (pretest $3.88{\pm}.36$, posttest $4.00{\pm}.38$, p<.001). However, no statistically significant difference was found in the Lecture-Based Learning (LBL) group (pretest $3.86{\pm}.43$, posttest $3.93{\pm}.17$). In terms of Learning Flow, there was statistically significant improvement in the PBL group (pretest $3.31{\pm}.41$, posttest $3.51{\pm}.42$). However, no significant change was identified in the LBL group (pretest $3.45{\pm}.42$, posttest $3.48{\pm}.47$. Academic motivation was improved in the LBL group (pretest $3.32{\pm}.30$, posttest $3.46{\pm}.32$, p=.002) as well as in the PBL group (pretest $3.26{\pm}.23$, posttest $3.47{\pm}.21$, p<.001). Both results were statistically significant. Conclusion: These results suggest that Problem-Based Learning could be more effective for nursing students in improving their academic achievement. Further studies need to be investigated.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.7
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• pp.492-507
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• 2010

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2009. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery and piping, and new and renewable energy. Various topics were covered in the field of general thermal and fluid flow such as an expander, a capillary tube, the flow of micro-channel water blocks, the friction and anti-wear characteristics of nano oils with mixtures of refrigerant oils, etc. Research issues mainly focused on the design of micro-pumps and fans, the heat resistance reliability of axial smoke exhaust fans, and hood systems in the field of fluid machinery and piping. Studies on ground water sources were executed concerning two well type geothermal heat pumps and multi-heat pumps in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included the heat transfer in thermoelectric cooling systems, refrigerants, evaporators, dryers, desiccant rotors. In the area of industrial heat exchangers, researches on high temperature ceramic heat exchangers, plate heat exchangers, frosting on fins of heat exchangers were performed. (3) In the field of refrigeration, papers were presented on alternative refrigerants, system improvements, and the utilization of various energy sources. Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and $CO_2$ were studied. Efforts to improve the performance of refrigeration systems were made applying various ideas of suction line heat exchangers, subcooling bypass lines and gas injection systems. Studies on heat pump systems using unutilized energy sources such as river water, underground water, and waste heat were also reported. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. In the area of cogeneration systems, papers on energy and economic analysis, LCC analysis and cost estimating were reported. Studies on ventilation and heat recovery systems introduced the effect on fire and smoke control, and energy reduction. Papers on district cooling and heating systems dealt with design capacity evaluation, application plan and field application. Also, the maintenance and management of building service equipments were presented for HVAC systems. (5) In the field of architectural environment, various studies were carried to improve indoor air quality and to analyze the heat load characteristics of buildings by energy simulation. These studies helped to understand the physics related to building load characteristics and to improve the quality of architectural environment where human beings reside in.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.12
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• pp.715-732
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• 2009

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2008. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends in thermal and fluid engineering have been surveyed in the categories of general fluid flow, fluid machinery and piping, new and renewable energy, and fire. Well-developed CFD technologies were widely applied in developing facilities and their systems. New research topics include fire, fuel cell, and solar energy. Research was mainly focused on flow distribution and optimization in the fields of fluid machinery and piping. Topics related to the development of fans and compressors had been popular, but were no longer investigated widely. Research papers on micro heat exchangers using nanofluids and micro pumps were also not presented during this period. There were some studies on thermal reliability and performance in the fields of new and renewable energy. Numerical simulations of smoke ventilation and the spread of fire were the main topics in the field of fire. (2) Research works on heat transfer presented in 2008 have been reviewed in the categories of heat transfer characteristics, industrial heat exchangers, and ground heat exchangers. Research on heat transfer characteristics included thermal transport in cryogenic vessels, dish solar collectors, radiative thermal reflectors, variable conductance heat pipes, and flow condensation and evaporation of refrigerants. In the area of industrial heat exchangers, examined are research on micro-channel plate heat exchangers, liquid cooled cold plates, fin-tube heat exchangers, and frost behavior of heat exchanger fins. Measurements on ground thermal conductivity and on the thermal diffusion characteristics of ground heat exchangers were reported. (3) In the field of refrigeration, many studies were presented on simultaneous heating and cooling heat pump systems. Switching between various operation modes and optimizing the refrigerant charge were considered in this research. Studies of heat pump systems using unutilized energy sources such as sewage water and river water were reported. Evaporative cooling was studied both theoretically and experimentally as a potential alternative to the conventional methods. (4) Research papers on building facilities have been reviewed and divided into studies on heat and cold sources, air conditioning and air cleaning, ventilation, automatic control of heat sources with piping systems, and sound reduction in hydraulic turbine dynamo rooms. In particular, considered were efficient and effective uses of energy resulting in reduced environmental pollution and operating costs. (5) In the field of building environments, many studies focused on health and comfort. Ventilation. system performance was considered to be important in improving indoor air conditions. Due to high oil prices, various tests were planned to examine building energy consumption and to cut life cycle costs.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.844-861
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• 2008

The papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during the year of 2007 have been reviewed. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro nano fluid, micropump and fuel cell. Traditional CFD was still popular and widely used in research and development. Studies about fans and pumps were performed in the field of fluid machinery. Characteristics of flow and fin shape optimization are studied in the field of piping system. (2) The research works on heat transfer have been reviewed in the field of heat transfer characteristics, heat exchangers, and desiccant cooling systems. The research on heat transfer characteristics includes thermal transport in pulse tubes, high temperature superconductors, ground heat exchangers, fuel cell stacks and ice slurry systems. For the heat 'exchangers, the research on pin-tube heat exchanger, plate heat exchanger, condensers and gas coolers has been cordially implemented. The research works on heat transfer augmenting tubes have been also reported. For the desiccant cooling systems, the studies on the design and operating conditions for desiccant rotors as well as performance index are noticeable. (3) In the field of refrigeration, many papers were presented on the air conditioning system using CO2 as a refrigerant. The issues on the two-stage compression, the oil selection, and the appropriate oil charge were treated. The subjects of alternative refrigerants were also studied steadily. Hydrocarbons, DME and their mixtures were considered and various heat transfer correlations were proposed. (4) Research papers have been reviewed in the field of building facilities by grouping into the researches on heat and cold sources, air conditioning and air cleaning, ventilation and fire research including tunnel ventilation, flow control of piping system, and sound research with drain system. Main focuses have been addressed to the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies were mostly focused on analyzing the indoor environment in various spaces like cars, old tombs, machine rooms, and etc. in an architectural environmental field. Moreover, subjects of various fields such as the evaluation of noise, thermal environment, indoor air quality and development of energy analysis program were researched by various methods of survey, simulation, and field experiment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.94-131
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• 2007

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2004 and 2005 has been done. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD and flow visualization(PIV, PTV and LDV methods) technologies were widely applied for developing facilities and their systems. (2) The research trends of the previous two yews are surveyed as groups of natural convection, forced convection, electronic cooling, heat transfer enhancement, frosting and defrosting, thermal properties, etc. New research topics introduced include natural convection heat transfer enhancement using nanofluid, supercritical cooling performance or oil miscibility of $CO_2$, enthalpy heat exchanger for heat recovery, heat transfer enhancement in a plate heat exchanger using fluid resonance. (3) The literature for the last two years($2004{\sim}2005$) is reviewed in the areas of heat pump, ice and water storage, cycle analysis and reused energy including geothermal, solar and unused energy). The research on cycle analysis and experiments for $CO_2$ was extensively carried out to replace the Ozone depleting and global warming refrigerants such as HFC and HCFC refrigerants. From the year of 2005, the Gas Engine Heat Pump(GHP) has been paid attention from the viewpoint of the gas cooling application. The heat pipe was focused on the performance improvement by the parametric analysis and the heat recovery applications. The storage systems were studied on the performance enhancement of the storage tank and cost analysis for heating and cooling applications. In the area of unused energy, the hybrid systems were extensively introduced and the life cycle cost analysis(LCCA) for the unused energy systems was also intensively carried out. (4) Recent studies of various refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and of alternative refrigerants including carbon dioxide. Efficiency of various compressors and expansion devices are also dealt with for better modeling and, in particular, performance improvement. Thermoelectric module and cooling systems are analyzed theoretically and experimentally. (5) According to the review of recent studies on ventilation systems, an appropriate ventilation systems including machenical and natural are required to satisfied the level of IAQ. Also, an recent studies on air-conditioning and absorption refrigeration systems, it has mainly focused on distribution and dehumidification of indoor air to improve the performance were carried out. (6) Based on a review of recent studies on indoor environment and building service systems, it is noticed that research issues have mainly focused on optimal thermal comfort, improvement of indoor air Quality and many innovative systems such as air-barrier type perimeter-less system with UFAC, radiant floor heating and cooling system and etc. New approaches are highlighted for improving indoor environmental condition as well as minimizing energy consumption, various activities of building control and operation strategy and energy performance analysis for economic evaluation.