• The Journal of the Korea Contents Association
• /
• v.21 no.3
• /
• pp.518-528
• /
• 2021

Based on the Self-Determination Theory and previous studies, this study confirmed that basic psychological needs among Self-Determination Theory have an indirect influence on the postpartum depression through mediation of spousal support and marital satisfaction. A sample of 313 mothers who raises her child within a year of giving birth completed a questionnaire survey, and a structural equation model was utilized to analyze the data. Results indicated that both the measurement model, and the hypothesized structural model fit to the data. Meanwhile, when compared with the hypothesized model in which the path between all variables is established, the competitive model excluding the path from spousal support to postpartum depression has no difference in fitness, and was relatively simple and adopted as the final model. In the final model, the link between basic psychological needs and postpartum depression was partially mediated by spousal support and marital satisfaction. In addition, marital satisfaction was found to mediate completely the relationship between spousal support and postpartum depression. Based on the results, it would be helpful to identify the status of basic psychological needs, spouse support, and marriage satisfaction in counseling related to postpartum depression.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.12
• /
• pp.807-818
• /
• 2020

In this study, hydrophones using acoustic sensors were used to estimate the amount of bedload discharge in a forested watershed. The reaction characteristics were analyzed through hydrophone flume tests and field tests, and the quantitative bedload discharge was calculated and compared with that measured by a pit sampler. The hydrophone reaction changed the pulse according to the flow rate change, but did not react to standard sand. The pulse was different depending on the particle size and weight, and accordingly, there was a specific channel showing a suitable response. For a hydrophone installed in the field, by using an automatic impact device, the reaction characteristics of each channel were analyzed to confirm normal operation of the sensor and the suitability of the output value of each channel. In addition, a suitable channel was selected for the estimation of bedload discharge. The bedload discharge formula was developed using a hydrophone pulse and the average flow rate, and was compared with the measured data in the pit sampler in the study site. As a result of the study, if a hydrophone is used for monitoring the bedload in forested watersheds, it is considered effective in quantitatively estimating the weight of bedload discharge.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.12
• /
• pp.570-577
• /
• 2020

This study is aimed at figuring out the influence of early childhood teachers' playfulness and sensitivity on play teaching efficacy. The subjects of the study were 262 early childhood teachers working in kindergarten and day care centers located in J City. The instruments were the Adult Playfulness Scale, the Sensitivity Scale, and the Play Teaching Efficacy Scale. The collected data were analyzed by using SPSS. In order to find out the general background of the early childhood teachers, frequency and percentage were used. In addition, in order to assess the relationships among playfulness, sensitivity, and the play teaching efficacy of an early childhood teacher, Pearson's correlation analysis was carried out. Lastly, for examination of the effects and a relative explanation of the effects of playfulness and sensitivity on play teaching efficacy in early childhood teachers, a multiple regression analysis was conducted. The results of this study are as follows. First, there was positive correlation among playfulness, sensitivity, and play teaching efficacy in the early childhood teacher. Second, play teaching efficacy of early childhood teachers was influenced by their playfulness and sensitivity. In conclusion, the significance of this study is that there was a significant correlation among playfulness, sensitivity, and play teaching efficacy in early childhood teachers, and that both of the first two variables were factors influencing play teaching efficacy.

• Journal of the Korean Geotechnical Society
• /
• v.36 no.12
• /
• pp.77-86
• /
• 2020

In this study, the importance of implied strength correction for shallow depths at a region of moderate to low seismicity with primary focus on its effect upon site natural period and mean period of the ground motion is investigated. In addition to the most commonly used Modified Kondner-Zelasko (MKZ) model, this paper uses a quadratic/hyperbolic (GQ/H) model that can capture the stress - strain response at large strains as well as small strain stiffness dependence. A total of six site profiles by downhole tests are used and 1D site response analyses are performed using three input motions with contrasting mean periods. The difference between non-corrected and corrected analyses is conditional on the site period as well as mean ground motion period. The effect of periods is analyzed by correlating them with the effective peak ground acceleration, maximum shear strains and amplification factors. The comparative study reveals that the difference is more prominent in soft sites with long site periods. Insignificant differences are observed when soil profiles are subjected to ground motion with very short mean period.

• Korean Journal of Cognitive Science
• /
• v.31 no.4
• /
• pp.137-154
• /
• 2020

Psychological properties of learners have influence on learning behaviors in various ways. The purpose of this study was to examine how the goal orientation of learners affected the learning time distribution method. Regulatory focus and theories of intelligence were measured and manipulated in order to differentiate participants' goal-oriented state. Two variables are known to be key variables influencing learner's goal orientation, inducing the approach-avoidance strategy and mastery-performance oriented attitude. In the experiment, the control focus was divided into two groups based on the inclination test score (regulatory Focus Questionnaire, RFQ), and TOI(theory of intelligence) was temporally induced through manipulation to confirm the interaction between the two variables. Participants were able to determine the order of learning freely by learning a set of Spanish-Korean word pairs and then selecting the items they would like to re-learn. Word pairs consisted of difficult or easy items, and learners could learn the same word many times if they wanted to. In the results, promotion-incremental group showed allocating difficult word-pairs in early time.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.36 no.4
• /
• pp.262-271
• /
• 2020

To restore a tooth with a fracture line extending below the marginal bone level, a surgical crown lengthening procedure accompanied by ostectomy could be considered to expose the fracture line and reestablish the biologic width. However, this procedure could lead to esthetic failure, especially in the anterior teeth. Therefore, orthodontic extrusion, which elevates the fracture line from within the alveolar socket without sacrificing the supporting bone and gingiva, is recommended. This technique allows for the proper placement of the crown on a sound tooth structure, with the reestablishment of the biologic width. Alternatively, surgical extrusion is an one-step procedure that is simpler and less time-consuming than orthodontic extrusion; placing and adjusting the orthodontic appliance does not require multiple visits. This study presents successful restoration in 2 cases with a crown-tooth root fracture of the maxillary central incisor treated using a multidisciplinary approach through orthodontic extrusion or surgical extrusion followed by successful restoration.

• Atmosphere
• /
• v.30 no.4
• /
• pp.439-454
• /
• 2020

This study investigates the change in the fine particulate matter (PM2.5) concentration and World Health Organization (WHO) air quality index (AQI) in East Asia (EA) under Shared Socioeconomic Pathways (SSPs). AQI is an indicator of increasing levels about health concern, divided into six categories based on PM2.5 annual concentrations. Here, we utilized the ensemble results of UKESM1, the climate model operated in Met Office, UK, for the analysis of long-term variation during the historical (1950~2014) and future (2015~2100) period. The results show that the spatial distributions of simulated PM2.5 concentrations in present-day (1995~2014) are comparable to observations. It is found that most regions in EA exceeded the WHO air quality guideline except for Japan, Mongolia regions, and the far seas during the historical period. In future scenarios containing strong air quality (SSP1-2.6, SSP5-8.5) and medium air quality (SSP2-4.5) controls, PM2.5 concentrations are substantially reduced, resulting in significant improvement in AQI until the mid-21st century. On the other hand, the mild air pollution controls in SSP3-7.0 tend to lead poor AQI in China and Korea. This study also examines impact of increased in PM2.5 concentrations on downward shortwave energy at the surface. As a result, strong air pollution controls can improve air quality through reduced PM2.5 concentrations, but lead to an additional warming in both the near and mid-term future climate over EA.

• Clean Technology
• /
• v.26 no.4
• /
• pp.270-278
• /
• 2020

Palladium (Pd) has been widely used in various industrial applications such as jewelry, catalyst, and dental materials despite its limited resources. It has been gaining attention to recover Pd with high purity from the spent materials. This study investigated the optimum conditions for the leaching and recovery of metallic Pd. The leaching parameters are HCl concentration, temperature, time, concentration of oxidants, and pulp density. 97.2% of Pd leaching efficiency was obtained in 3 M HCl with 3 vol% oxidants at 80℃ for 60 min. The ratio of hydrogen peroxide to sodium hypochlorite played a critical role in the leaching efficiency due to the supply of Cl- ions in the leachate. Moreover, the complete recovery of Pd in the leachate was achieved at 80℃ with 0.3 formic acid/leachate after adjusting the pH value of 7. This situation was ascribed to the decomposition of formic acid into hydrogen gas and carbon dioxide at 80℃. ICP-AES and XRD characterized the recovered Pd powder, and the purity of the recovered powder was found to be 99.6%. Consequently, the recovered Pd powder with high purity could be used in circuits, catalyst precursors, and surgical instruments.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.12
• /
• pp.310-319
• /
• 2020

Korea estimates the traffic noise by measuring the total traffic noise when the traffic passes (SPB; Statistical Pass-By). Another method (CPX; Close Proximity) directly measures the tire/road noise by installing a microphone near the tire. The CPX method is not a formal test method in Korea. There has been little research between CPX and SPB. This study proposes a method for estimating SPB, using the CPX, which is easy to measure. This study used the results of a large-scale test conducted by Korea Expressway Corporation (KEC) and a research paper on CPX in this section. The results by the KEC showed that the low noise pavement has a noise reduction of 10.4dB. In CPX research, the noise reduction was 10.7dB and was similar to 10.4dB in SPB. This study shows why the noise reduction is the same regardless of the position, the reason that the amount of noise reduction is similar, the difference of the noise according to the position of the microphone using the concept of noise summation and distance reduction. This study shows that including the CPX as a variable in the traffic noise prediction program is very important to improve noise prediction reliability.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.19 no.6
• /
• pp.96-106
• /
• 2020

To solve the limitation of traffic monitoring that occur from embedded sensor such as loop and piezo sensors, the thermal imaging camera was installed on the roadside. As the length of Class 1(passenger car) is getting longer, it is becoming difficult to classify from Class 3(2-axle truck) by using an embedded sensor. The collected images were labeled to generate training data. A total of 17,536 vehicle images (640x480 pixels) training data were produced. CNN (Convolutional Neural Network) was used to achieve vehicle classification based on thermal image. Based on the limited data volume and quality, a classification accuracy of 97.7% was achieved. It shows the possibility of traffic monitoring system based on AI. If more learning data is collected in the future, 12-class classification will be possible. Also, AI-based traffic monitoring will be able to classify not only 12-class, but also new various class such as eco-friendly vehicles, vehicle in violation, motorcycles, etc. Which can be used as statistical data for national policy, research, and industry.