• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.841-846
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• 2019

The purpose of this work is to manufacture of high efficiency water-treatment filter that is equal to imported products or even higher in terms of quality and even develop the manufacturing process. The filtration efficiency of the developed filter was 93~99%, which was better or similar to that of domestic filter (82~97.5%) and Japanese filter (92.5~98%). The pressure loss(durability) along with the amount of contaminant particles was significantly smaller than that of domestic products, and showed $0.1kg_f/cm^2$ less than that of Japanese products. In addition, at the cost side of production, the developed cartridge filter can be produced with 50% of the current price compared to that of Japanese products. Therefore, it is possible to replace the imported Japanese products as well as domestic products.

• The Korean Journal of Food And Nutrition
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• v.34 no.4
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• pp.372-380
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• 2021

In this study, data from the 7th (2016~2018) and 8th (2019) Korea National Health and Nutrition Examination Surveys were used, which included 5,325 subjects. Health behavior, dietary and nutrient intake status, physical measurement and biochemical characteristics, and risk factors for elderly related chronic diseases were classified and analyzed according to the changing composition of single households and other households in the current society. As a result, the ratio of current smokers and drinkers in young adult single households, walking less than 30 minutes per day, subjective health status was poor, breakfast rate less than three times per week, eating out frequency more than once a day, lipid intake ratio to total calories, saturation fatty acid intake were significantly higher. In addition, waist circumference, and diastolic blood pressure were significantly higher. However, dietary fiber intake level was significantly lower. The results for hypertension, which is the representative chronic disease that causes old age-related chronic diseases, were significantly higher in single households (ORs=1.400 (95% CI: 1.095, 1.791), p=0.007). Although young adults may not have showed particularly serious health problems yet, education is believed as important to recognize and prevent age-related disease risk factors.

• Fashion & Textile Research Journal
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• v.21 no.2
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• pp.133-140
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• 2019

This study developed smart fashion prototypes that provide utilitarian functionality by combining Fashion and Electronics regarding the IT focused convergence tendency in modern industries. A convergence R&D workshop was performed by Fashion design majors and Engineering majors for the study. As a result, 5 functional smart fashion prototypes were developed and the outline of each prototype are as follows. The $1^{st}$ prototype, 'Hidden Camera Detecting Coat' focused on gender-related crimes. The coat uses infrared lighting and LED technologies to provide a function to detect hidden cameras in suspicious public spaces such as toilets. The $2^{nd}$ prototype, 'Heating-massage Suit' targeted patients with musculoskeletal system difficulties. The suit uses heating and vibration technologies to provide a heating massage treatment for patients with ongoing difficulties in their daily lives. The $3^{rd}$ prototype is an air-bag jacket to prevent sexual molestation on public transportation. The jacket extends its volume through pressure sensing, air compressing, motors and 3D-printing technology to secure the wearer's personal preventive space between the user's body and others. The $4^{th}$ prototype is a town wear for people suffering from synesthesia. People with synesthesia inadvertently see colors when exposed to certain sounds. This town wear uses sound sensing, air compressing, motors and 3D-printing technology to provide sound prevention and a comfortable sound playing function. The $5^{th}$ prototype is a set of a vest and a gloves for visually impaired people. The vest and gloves uses DMS, voice playing, vibration technology to provide distance measuring and warning functions.

• Atmosphere
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• v.29 no.2
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• pp.115-129
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• 2019

Surface winds over the ocean influence not only the climate change through air-sea interactions but the coastal erosion through the changes in wave height and direction. Thus, demands on a reliable projection of future changes in surface winds have been increasing in various fields. For the future projections, climate models have been widely used and, as a priori, their simulations of surface wind are required to be evaluated. In this study, we evaluate the climatological mean surface winds over the Korean Waters simulated by five regional climate models participating in Coordinated Regional Climate Downscaling Experiment (CORDEX) for East Asia (EA), an international regional climate model inter-comparison project. Compared with the ERA-interim reanalysis data, the CORDEX-EA models, except for HadGEM3-RA, produce stronger wind both in summer and winter. The HadGEM3-RA underestimates the wind speed and inadequately simulate the spatial distribution especially in summer. This summer wind error appears to be coincident with mean sea-level pressure in the North Pacific. For wind direction, all of the CORDEX-EA models simulate the well-known seasonal reversal of surface wind similar to the ERA-interim. Our results suggest that especially in summer, large-scale atmospheric circulation, downscaled by regional models with spectral nudging, significantly affect the regional surface wind on its pattern and strength.

• Tribology and Lubricants
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• v.34 no.6
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• pp.279-283
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• 2018

In this study, we investigate the behavior of abrasive particles and change of the stick-slip pattern according to chemical mechanical polishing (CMP) process parameters when a large number of abrasive particles are fixed on a pad. The CMP process is simulated using the finite element method. In the simulation, the abrasive grains are composed of those used in the actual CMP process. Considering the cohesion of the abrasive grains with the start of the CMP process, abrasive particles with various sizes are fixed onto the pad at different intervals so that stick-slip could occur. In this analysis, we determine that when the abrasive particle size is relatively large, the stick-slip period does not change as the pressure increases while the moving speed is constant. However, if the size of the abrasive grains is relatively small, the amount of deformation of the grains increases due to the elasticity of the pad. Therefore, the stick-slip pattern may not be observed. As the number of abrasive particles increases, the stick-slip period and displacement decrease. This is consistent with the decrease in the von Mises yield stress value on the surface of the wafer as the number of abrasive grains increases. We determine that when the number of the abrasive grains increases, the polishing rate, and characteristics are improved, and scratches are reduced. Moreover, we establish that the period of stick-slip increases and the change of the stick-slip size was not large when the abrasive particle size was relatively small.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.6
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• pp.84-93
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• 2018

Three-dimensional (3D) numerical simulations have been carried out to study how coolant injection conditions influence the cooling efficiency and projectile ejection performance in a mixture-gas ejection system (or gas-steam launch system). The 3D single-phase computational model was verified using a 1D model constructed with reference to the previous research and then a two-phase flow computation simulating coolant injection on to hot gas was performed using a DPM (Discrete Phase Model). As a result of varying the coolant flow rate and number of injection holes, cooling efficiency was improved when the number of injection holes were increased. In addition, the change of the coalescence frequency and spatial distribution of coolant droplets caused by the injection condition variation resulted in a change of the droplet diameter, affecting the evaporation rate of coolant. The evaporation was found to be a critical factor in the design optimization of the ejection system by suppressing the pressure drop while the temperature decreases inside the breech.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.1
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• pp.52-60
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• 2019

In this study, the performance and structure of a parallel ejector comprised of multiple single ejectors were confirmed through numerical analysis. The same design variables (mass suction ratio, compression ratio, and expansion ratio) relevant to the performance of a single ejector were considered in the design of the parallel ejector. Analytical results showed that there was no significant difference in the performance of either system related to the operating mass suction ratio; however, the systemsize was significantly reduced. In addition, it was confirmed that when ejectors of the same performance capacity are arranged in parallel, the combined mass suction ratio is lower than that of the single ejector, allowing a lower pressure to be realized. The results of the analysis indicated that the parallel ejector's performance is not significantly different from that of any single ejector, but confirmed that the parallel ejector can offer a configurationdependent advantage in size and operation.

• The Journal of the Acoustical Society of Korea
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• v.38 no.4
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• pp.443-449
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• 2019

To protect the patient's internal organs when a patient with cardiovascular disease occurs, it is important to reduce the elapsed time by providing emergency medical services. Decisions for conducting cardiopulmonary resuscitation are mainly made using the carotid palpation method, which directs the pulse of the carotid artery, which can diagnose the patient's condition according to one's own subject and cause cerebral blood flow to be blocked by excessive pressure in the carotid due to the weaken cardiopulmonary function. In this study, we developed a multimodal patch-type probe based on multi-channel ultrasound Doppler pairs and oxygen saturation measurement modules which can monitor cardiopulmonary functions. From the in-vivo experiments, the developed probe can be utilized as a novel tool that can increase the survival rate of cardiovascular disease patients by objectively monitoring the cardiopulmonary function of the patient quantitatively and promptly in an emergency situation.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.6
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• pp.78-84
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• 2020

The performance of pintle thruster is analyzed by using the pintle thruster performance analysis model which integrating the element models introduced in Part I. To verify the performance analysis, the results of the developed program are compared with the experimental data of kerosene/hydrogen peroxide liquid pintle thrusters. Based on the results, the characteristics of the pintle thruster are analyzed. The sensitivity analysis is performed to investigate the effect of thruster shape and operation parameters on performance characteristics using both OAT and scatter plot methods. The four performance parameters such as droplet diameter, film flow rate, O/F ratio, and nozzle throat diameter are evaluated to investigate their effects on characteristic speed, combustor pressure, and specific thrust.

• Journal of Korean Neurosurgical Society
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• v.64 no.4
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• pp.631-643
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• 2021

Objective : Here, we evaluated whether cerebrospinal fluid (CSF) profiles and their changes after intraventricular chemotherapy for leptomeningeal carcinomatosis (LMC) could predict the treatment response or be prognostic for patient overall survival (OS) along with clinical factors. Methods : Paired 1) pretreatment lumbar, 2) pretreatment ventricular, and 3) posttreatment ventricular samples and their CSF profiles were collected retrospectively from 148 LMC patients who received Ommaya reservoir installation and intraventricular chemotherapy. CSF profile changes were assessed by calculating the differences between posttreatment and pretreatment samples from the same ventricular compartment. CSF cell counts were further differentiated into total and other based on clinical laboratory reports. Results : For the treatment response, a decreased CSF 'total' cell count tended to be associated with a 'controlled' increase in intracranial pressure (ICP) (p=0.059), but other profile changes were not associated with either the control of increased ICP or the cytology response. Among the pretreatment CSF profiles, lumbar protein level and ventricular cell count were significantly correlated with OS in univariable analysis, but they were not significant in multi-variable analysis. Among CSF profile changes, a decrease in 'other' cell count showed worse OS than 'no change' or increased groups (p=0.001). The cytological response was significant for OS, but the hazard ratio of partial remission was paradoxically higher than that of 'no response'. Conclusion : A decrease in other cell count of CSF after intraventricular chemotherapy was associated with poor OS in LMC patients. We suggest that more specific CSF biomarkers of cancer cell origin are needed.