• Journal of Ocean Engineering and Technology
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• v.33 no.1
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• pp.1-9
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• 2019

This paper considers a numerical assessment of the self-propulsion performance of a damaged ferry carrying cars in irregular waves. Computational fluid dynamics(CFD) simulations were performed to see whether the ferry complied with the Safe Return to Port (SRtP) regulations of Lloyd's register, which require that damaged passenger ships should be able to return to port with a speed of 6 knots (3.09 m/s) in Beaufort 8 sea conditions. Two situations were considered for the damaged conditions, i.e., 1) the portside propeller was blocked but the engine room was not flooded and 2) the portside propeller was blocked and one engine room was flooded. The self-propulsion results for the car ferry in intact condition and in the damaged conditions were assessed as follows. First, we validated that the portside propeller was blocked in calm water based on the available experimental results provided by KRISO. The active thrust of starboard propeller with the portside propeller blocked was calculated in Beaufort 8 sea conditions, and the results were compared with the experimental results provided by MARIN, and there was reasonable agreement. The thrust provided by the propeller and the brake horsepower (BHP) with one engine room flooded were compared with the values when the engine room was not flooded. The numerical results were compared with the maximum thrust of the propeller and the maximum brake horse power of the engine to determine whether the damaged car ferry could attain a speed of 6 knots(3.09 m/s).

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.267-274
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• 2018

Though the wet bottom ash has been used as a type of lightweight aggregate, dry bottom ash, new type bottom ash from coal combustion power plant, has scarcely researched. It is excellent lightweight aggregate in the view point of construction material. This study is performed to check the applicability of dry bottom ash as a fine aggregate in lightweight aggregate concrete, by analyzing various properties of fresh and hardened concrete. We get results that the slump of concrete is within the target range at less than 75% replacement rate of dry bottom ash, the air content is not affected by the replacement rate of dry bottom ash, the bleeding capacity is less than $0.025cm^3/cm^2$ at 75% under of the replacement rate of dry bottom ash, and the compressive strength of concrete show 90% or more comparing the base mix while initial strength development is a little low. Oven dry unit weight of concrete is reduced by 8.9% when replaced 100% dry bottom ash, and dry shrinkage tends to decrease depending on increase of replacement rate of dry bottom ash. Modulus of elasticity of concrete shows no decease at 50% over of the replacement rate of dry bottom ash, while modulus of elasticity of concrete decreases when the replacement rate increases further. The dry bottom ash, when used as a fine aggregate in lightweight concrete, can be used effectively without any deterioration in quality.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.166-173
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• 2019

In this paper, the reaction properties of silica source in the accelerated curing conditions using autoclave and the fundamental properties of inorganic Micro Defect Free(MiDF) concrete using silica source are studied. Studies show that Si ions elution rate from silica source in autoclave curing is higher in amorphous source. In tap water conditions, solids which is source after autoclaved curing show a higher mass reduction in amorphous materials, which is attributed to the higher elution rate of ion. In $Ca(OH)_2$ solution conditions, amorphous materials show higher mass increase, due to increase in C-S-H minerals. From experiment for influence on the properties of MiDF concrete by using nano silica materials, the specimen with silica fume shows an increase in compressive strength and a decrease in absorption depending on replacement rate up to 5.5%, while nano silica with amorphous phase and high-fineness shows a decrease in compressive strength and decrease in the water absorption. The specimen with nano silica increases the pore below 10,000nm, but reduces pore between 10,000 and 100,000nm. The above results show that the porosity and absorption rate of MiDF concrete can be reduced by using amorphous nano-size silica. However, to reduce the pore of 50 to 10,000nm, better dispersion of nano material in the cement matrix will be necessary. We will focus on the this item in the next research.

• Journal of Convergence for Information Technology
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• v.9 no.9
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• pp.67-77
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• 2019

This study was conducted to examine effects of the spiritual care education program on self esteem, communication, existential well-being and spiritual care competence in nurses. A non-equivalent control group, non-synchronized with pre-posttest design was used. The participants were 63 nurses(30 in an experimental group and 33 in a control group)attending a bachelor program of C Colledge in G metropolitan city. The experimental group attended 7 sessions of a SCE(Spiritual Care Education) program. Sessions were 90 minutes each, held once per week for 7 weeks. The scores for self-esteem, communication, existential well-being and spiritual care competence were measured before and after the treatment. Data were collected between October 10 and December 5, 2017 in an experimental group, April 24 and June 5, 2018 in a control group. Data were analyzed using Chi-square, Fisher's exact test, independent t-test using SPSS/WIN 21.0. The existential well-being(p<.025) and spiritual care competence(p<.001) were significantly increase in the experimental group compared to the control group after the intervention. Results suggest that this SCE program could be effective in increasing the existential well-being and spiritual care competence of nurses.

• Journal of Life Science
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• v.29 no.2
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• pp.147-151
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• 2019

Soybean [Glycine max (L.) Merr.] is grown worldwide for its high protein and oil content. Anthocyanins from black soybean seed coats are known to have many pharmaceutical effects. Soybean cultivars with large seed sizes and black seed coats are needed by soybean farmers. However, antinutritional factors, like protein, stachyose, and Kunitz trypsin inhibitor (KTI) exist in raw mature soybeans. Genetic elimination or reduction of these components is needed in soybean breeding. The objective of this research was to develop new a soybean strain with black seed coats and green cotyledons that was KTI protein free and low in stachyose. Six parents were used. The presence or absence of KTI protein was detected using the Western blot technique. The content of stachyose in mature seeds was detected using HPLC. One new strain was selected from 11 $F_2$ plants with black seed coats and green cotyledons that lacked KTI protein. The new strain had black seed coats and green cotyledons and was KTI protein free and low in stachyose. The plant height of the new strain was 66 cm, and its 100-seed weight was 28.4 g. The stachyose content of the new strain was 2.59 g/kg. The new strain developed in this research will be used to develop new cultivars that are KTI protein free and low in stachyose.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.173-177
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• 2011

In this study, the formation of $AlPO_4$-type porous materials from alum sludge was investigated. The materials were synthesized by the reaction of aluminum hydroxide and phosphoric acid with an organic template. Cationic surfactant, natural humic acid, and amino acids were used for the organic template. The residual organic templates were removed by calcination at $600^{\circ}C$ in the air. Powder X-ray diffraction patterns showed the charicteristic patterns of the $AlPO_4$-type porous materials. The morphology of the material was examined using a scanning electron microscopy. The coordination environment of $Al^{3+}$ ion was investigated by $^{27}Al$ MAS NMR technique. Both tetrahedrally and octahedrally coordinated$Al^{3+}$ ions were found in the as-synthesized samples while all $Al^{3+}$ ions were tetrahedrally coordinated in the calcined products. The development of mesopore in the solid material was confirmed by the measurement of BET specific surface area. Finally, they were used for removal of toxic formaldehyde from the air and the formaldehyde molecules were adsorbed on the surface of pores. In conclusion, $AlPO_4$-type porous materials from alum sludge might be applicable in the removal of toxic volatile organic compounds from the air.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.501-507
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• 2011

To develop environmental-friendly insulating composite materials, natural cellulose and porous ceramic balls were used as core materials and activated Hwangtoh was used as a binder. Various specimens were prepared with different water/binder ratios and core material/binder ratios. The physical properties of these specimens were then investigated through compressive strengths, flexural strengths, absorption test, hot water resistance test, pore analysis, thermal conductivity, and observation of micro-structures using scanning electron microscope. Results showed that the maximum compressive strength varied appreciably with the water/binder ratios and core material/binder ratios, but the flexural strength increased with the core material/binder ratios regardless of water/binder ratios. The compressive strength and the flexural strength measured after the hot water resistance test decreased remarkably compared to those measured before test. The pore analysis measured after the hot water resistance test showed that total pore volume, porosity and average pore diameter decreased, while bulk density increased by the acceleration of hydration reaction of binder in the hot water. The thermal conductivity decreased gradually with an increase of core material/binder ratios. It can be evaluated that the composite insulation materials having good insulating properties and mechanical strengths can be used in the field.

• Journal of Korean Academy of Dental Administration
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• v.7 no.1
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• pp.39-43
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• 2019

Smartphone usage has become so common that it has reached 2 billion people in the last year. As a result of this, hospitals have started making use of smartphones at various medical sites and research services for patients. This study aimed to establish support for developing a long distance program for patients with implants who have difficulty visiting clinics or with busy modern lives, by using smartphones for oral hygiene management instruction. The data were collected for 12 weeks, from July 24 to October 21, 2015, for patients who agreed to participate in the study. Although the subjects found the process of transferring photos via smartphone to be cumbersome (75%), the satisfaction level of the oral hygiene management program was excellent for all participating patients, and they all wanted to continue with further management using this process. The results from the phone satisfaction survey showed that oral hygiene self-management after oral hygiene control training by smartphones was mostly equal to previous habits (87.5%) or had partially increased but had not decreased. The need for data on more varied age groups and the issues of protecting the security of personal information on smartphones require further study. However, our study confirmed the efficacy of using electronic media (smartphones) for oral hygiene management in patients with a dental implant due to their improvement of oral hygiene performance as evidenced by less bleeding from probing on post-program visit.

• Journal of Korean Academy of Dental Administration
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• v.8 no.1
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• pp.1-7
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• 2020

Dental settings have unique characteristics that warrant specific infection control considerations, including (1) prioritizing the most critical dental services and provide care in a way that minimizes harm to patients due to delayed care, or harm to personnel from potential exposure to persons infected with the COVID-19 disease, and (2) proactively communicate to both personnel and patients the need for them to stay at home if sick. For health care, an interim infection prevention and control recommendation (COVID-19) is recommended for patients suspected of having coronavirus or those whose status has been confirmed. SARS-CoV-2, which is the virus that causes COVID-19, is thought to be spread primarily between people who are in close contact with one another (within 6 feet) through respiratory droplets that are produced when an infected person coughs, sneezes, or talks. Airborne transmission from person-to-person over long distances is unlikely. However, COVID-19 is a new disease, and there remain uncertainties about its mode of spreads and the severity of illness it causes. The virus has been shown to persist in aerosols for several hours, and on some surfaces for days under laboratory conditions. COVID-19 may also be spread by people who are asymptomatic. The practice of dentistry involves the use of rotary dental and surgical instruments, such as handpieces or ultrasonic scalers, and air-water syringes. These instruments create a visible spray that can contain particle droplets of water, saliva, blood, microorganisms, and other debris. While KF 94 masks protect the mucous membranes of the mouth and nose from droplet spatter, they do not provide complete protection against the inhalation of airborne infectious agents. If the patient is afebrile (temperature <100.4°F)* and otherwise without symptoms consistent with COVID-19, then dental care may be provided using appropriate engineering and administrative controls, work practices, and infection control considerations. It is necessary to provide supplies for respiratory hygiene and cough etiquette, including alcohol-based hand rub (ABHR) with 60%~95% alcohol, tissues, and no-touch receptacles for disposal, at healthcare facility entrances, waiting rooms, and patient check-ins. There is also the need to install physical barriers (e.g., glass or plastic windows) in reception areas to limit close contact between triage personnel and potentially infectious patients. Ideally, dental treatment should be provided in individual rooms whenever possible, with a spacing of at least 6 feet between the patient chairs. Further, the use of easy-to-clean floor-to-ceiling barriers will enhance the effectiveness of portable HEPA air filtration systems. Before and after all patient contact, contact with potentially infectious material, and before putting on and after removing personal protective equipment, including gloves, hand hygiene after removal is particularly important to remove any pathogens that may have been transferred to the bare hands during the removal process. ABHR with 60~95% alcohol is to be used, or hands should be washed with soap and water for at least 20 s.

• Journal of Korean Academy of Dental Administration
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• v.9 no.1
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• pp.14-24
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• 2021

Dentists and dental hygienists are major collaborators, as expressed by the concept of "Four-handed dentistry." Dentists are guaranteed their legal duties and rights in accordance with the Medical Act, whereas dental hygienists are currently stipulated in the scope of their legal duties under the Act on Medical Technicians. However, there is a difference between the actual work and the legal work performed by dental hygienists; therefore, the work is dependent on many legal controversies and authoritative interpretations. The purpose of this study is, first, to develop a reliable questionnaire tool regarding the actual work performed by dental hygienists in dental hospitals and clinics, and second, to examine the awareness of the appropriateness of legal work based on the developed questionnaire. The target subjects of the survey were dental hygienists and dentists, and the dental hygienists were those who worked in dental hospitals and clinics as license reporters of the Korean Dental Hygienists Association. A total of 1,294 dental hygienists and 39 dentists were included in the final analysis. In the dental hygienist group, 19 items received the response "appropriate for legal work" in over 90% of cases, accounting for 25% of the total 76 items. In addition, in a total of 31 items, more than 80% of the responses were appropriate for legal work. Among them, the highest was 'Scailing' (97.7%), followed by "Extraoral-Panorama" (97.1%). In the dentist group, 10 out of 76 items showed over 90% adequacy for legal work, and among them, "instrument cleaning and sterilization" was the highest at 100%. It was followed by "Intraoral radiography," "Scailing," and "Toothpick method, TPM" with 97.4%. In the case of dentists, 28 out of a total of 76 items showed an appropriateness of more than 80% for legal work. This study comprehensively investigated the actual work of dental hygienists in line with timely and appropriate social issues and provided reliable statistics in evidence-based dentistry.