• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.265-271
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• 2019

The aim of this paper was to improve the shortcomings of Pitcher Concrete, a conventional ethylene-based polymer used in combination with the other components, and present basic data for use as improved road pavement material by applying an acrylic polymer. Existing ethylene polymer-based pitcher concrete materials were selected. Acrylic polymer was then added and the resulting mixture was evaluated. The compressive strength of the existing ethylene-based polymer pitcher concrete combination was low due to the large air gap, and a compressive strength of 24MPa was observed on the 28th day of road use, as defined by KS for an acrylic polymer-based pitcher concrete combination. Regarding the bending strength, the combined strength of the acrylic polymer-based pitcher concrete was excellent, and the factor of the pitcher was measured above the reference, 0.1(mm/s), in all variables. All parameters measured were less than 1%. The acrylic polymer mixing characteristics were able to maintain the dynamic modulus of elasticity for more than 120 cycles, but not more than 80 cycles for the other combinations. Therefore, the addition of more acrylic polymer than conventional ethylene polymer base is effective in improving the durability.

• Journal of Korean Critical Care Nursing
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• v.14 no.2
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• pp.12-23
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• 2021

Purpose : The purposes of this study were to examine the levels of job stress, perceptions of the patient safety culture, and patient safety nursing activities, and to identify factors influencing patient safety nursing activities among intensive care unit (ICU) nurses. Methods : For this cross-sectional study, data were collected from 161 ICU nurses working in two university-affiliated hospitals in Gyeonggi-do between June 30 and July 30, 2020. The data were analyzed with descriptive statistics, an independent t-test, a one-way ANOVA, the Pearson correlation method, and multiple regression using the SPSS program. Results : The average levels of job stress, perception of patient safety culture, and patient safety nursing activities were 3.48, 3.44, and 4.45 out of 5, respectively. Multiple regression showed that perception of patient safety culture and career in current workplace were found to be statistically significant correlates of patient safety nursing activities. Conclusion : In order to promote patient safety nursing activities, patient safety culture needs to be incorporated into the education of ICU nurses. Perception of patient safety should be enhanced to improve patients safety nursing activity.

• Journal of the Korean Wood Science and Technology
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• v.31 no.1
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• pp.52-60
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• 2003

The physical properties of small hardwood and softwood specimens treated with liquid ammonia were investigated. The specimens treated for 4 or 18 hours were compared with the controls. The EMCs of the liquid ammonia treated specimens were higher than those of the controls when conditioned at the same humidities. However once oven-dried they didn't show any significant differences in EMCs. With the increase of liquid ammonia treatment time specimens shrank in radial and tangential directions, but not in longitudinal direction. As liquid ammonia treatment time increased the ultrasonic velocities of specimens decreased and their densities increased, thus their dynamic MOEs decreased. For chestnut specimens the presteamed were more plasticized than the liquid ammonia treated. Incising on the surfaces of specimens didn't improve liquid ammonia permeability in both hardwoods and softwoods. Liquid ammonia treatment was very effective for plasticizing 5 mm thick softwoods. Relative dielectric constants and thermal conductivities were measured with both liquid ammonia treated and control specimens.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.386-394
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• 2022

In this study, the mechanical properties and frost resistance of concrete with steel and nylon fibers were experimentally investigated. Both of OPC concrete with 100 % ordinary portland cement and SGC concrete replaced with 50 % GGBFS were manufactured to evaluate effects of fibers to the performance of concrete. Compressive and split tensile strength, ultrasonic pulse velocity and surface electric resistivity measurements of concrete were carried out at a predetermined interval. In addition, the freezing & thawing resistance of concrete in accordance with ASTM C666 standard was also examined. As a result, it is seemed that the effect of fibers was remarkable to improve the mechanical properties and frost resistance of concrete, especially for the concrete incorporating steel fiber.

• The Journal of the Acoustical Society of Korea
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• v.40 no.6
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• pp.671-677
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• 2021

The present study aims to investigate the influence of the water to binder ratio of finishing mortar on the floor impact sound of apartments. For this, same resilient materials Expanded Polystyrene (EPS) with constant dynamic stiffness and different mortar layers with 52 %, 66 % and 72 % water to binder ratio respectively were used to build floating floor structures on which floor impact sounds were measured in standard testing facilities. As a result, it was found that light-weight floor impact sound was transmitted well when the water to binder ratio was 52% due to the high density. In case of heavy-weight floor impact sounds, since water to binder ratio of finishing mortar becomes higher as the weight of upper layer of resilient material lighter, it was shown that the natural frequency of floating floor structure moves to 63 Hz bandwidth which eventually cause a higher sound pressure level of floor impact sound. Thus, effect of water to binder ratio of mortar on the heavy-weight floor impact sounds was investigated.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.1
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• pp.65-70
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• 2023

The effect of improvement by keeping the former as the priority was examined through an evaluation of the role of the blood transfusion management (BTM) division. This division manages the status of blood for transfusion, evaluates the adequacy of blood transfusion (EABT), monitors and responds to the occurrence of transfusion-related side effects, and performs other tasks necessary for BTM. Although the establishment and operation of the BTM division can lead to the efficient evaluation of transfusion adequacy, there are disadvantages in that it takes time for EABT and it is difficult for the staff in charge of the BTM division to evaluate the adequacy of all the blood. In the future, it is essential to introduce a BTM division and committee specific to Korean patients to implement safe and appropriate BTM in medical institutions, and to assist medical institutions in training their personnel.

• Journal of the Korean Geosynthetics Society
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• v.22 no.3
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• pp.71-86
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• 2023

Rock blasting tests using underground penetration-type displacement sensors were conducted, and three-dimensional finite element numerical analyses were performed to assess their applicability and mitigate slope hazards during rock blasting. Additionally, parameters influencing vibration velocity were investigated during the tests. The results confirmed that underground penetration-type displacement sensors are suitable for monitoring rock slope behavior, and the numerical analyses revealed that the most influential parameter on vibration velocity during rock blasting is the unit weight. Furthermore, it was observed that vibration velocity decreases significantly with distance from the blast source, and proximity to the source leads to substantial variations in vibration velocity due to differences in elastic modulus and unit weight. Changes in internal friction angle and adhesive strength had minimal impact.

• Journal of the Korean Geotechnical Society
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• v.24 no.4
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• pp.47-55
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• 2008

This study was carried out to investigate and analyse the influence of maximum size of coarse aggregate and quality control of aggregate on the properties of shotcrete through the laboratory and field test. From the results of the test, as the maximum size of coarse aggregate decreased from 13 mm to 8 mm, plasticity property declined and compressive strength and dynamic modulus of elasticity of hardened concrete increased remarkably, so it was found that the aggregate size 8 mm was superior to 13, 10 mm in fluidity, constructability and durability. Therefore, it was advisable for well maximum size of coarse aggregate to apply to the 8mm aggregates through the Ready-mixed Method for quality control and minimum segregation.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.1
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• pp.73-77
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• 2022

Blood products (BPs) can only be obtained through blood donation and hence represent a finite resource. BPs should therefore be used conservatively. However, BPs are being used indiscriminately without evidence. The purpose of this study was to evaluate the reasons for the use of BPs and their appropriateness. The investigation was carried out based on hemoglobin levels. Data were obtained from Nov 1, 2020, to Oct 31, 2021, from a hospital's OCS/EMR systems. The BPs were dispensed in 21,303 cases, and the number of hemoglobin levels >7.0 g/dL or higher among red blood cell drugs used by each treatment department was 1,173 (>7.0 g/dL). The misuse of blood transfusions is increasing social costs, with the adequacy of transfusion becoming increasingly important. Hence, each medical institution should review the transfusion guideline evaluation index, check the status of the release of BPs, and institute educational programs covering transfusion guidelines and continually evaluate their adequacy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1D
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• pp.35-43
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• 2008

This paper mainly deals with the performance evaluation of 33 asphalt sections of Korea Expressway Corporation Test Road (KECTR) during the past four years. Since the construction of the KECTR in December 2002, key performance indicators of asphalt pavements have been collected five times with an Automatic Road Analyzer (ARAN), and have been analyzed for permanent deformation, surface distress, and road roughness. Linear viscoelastic characteristics of four dense graded HMAs used in KECTR were investigated with a series of complex modulus test. The effect of air void in HMAs on dynamic modulus was investigate at two air void contents for a surface course HMA (19 mm Nominal Maximum Size of Aggregate). Layer densification due to traffic was estimated from air void contents of field cored samples, and was correlated with pavement distresses and performances. One of findings of this study was that both permanent deformation and cracking were suspectible to pavement temperatures, rather than traffic. However, it was found that road roughness was mostly affected by traffic loading.