• Clinical and Experimental Pediatrics
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• v.48 no.11
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• pp.1162-1165
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• 2005

Purpose : The objective of this survey was to develop an operational plan for breast feeding education. In order to comprehend current breast feeding patterns, we aimed to examine the knowledge, attitude and practices regarding breast feeding of mothers and to compare the data with a similar study done 6 years ago. Methods : A total of 127 mothers who delivered healthy babies at Ewha Womans University Dongdaemun Hospital were interviewed and asked to complete a survey on their perception of breast feeding during their postpartum stay in the hospital. A follow up phone interview was carried out at 1, 2 and 3 months after delivery and similar questions were asked. Results : At the time of delivery, 96.1 percent of mothers planned to breast feed, including 73.2 percent of exclusive breast feeding and 22.8 percent of mixed feeding. The duration of breast feeding planned was mostly 7-12 months. Breast feeding had been recommended by family members. Between 1-3 months, exclusive breast feeding was maintained at least 50 percent but a large number of mothers who had practiced mixed feeding changed to formula feeding. This trend demonstrates an increase in the rate of breast feeding at 3 months compared to a similar study done in 1999. The main reasons for discontinuing breast feeding were insufficient amount of milk(35.0 percent) and return to work(27.5 percent). Conclusion : Breast feeding rate has increased in Korea since 1999 but failure to continue exclusive breast feeding still occurs mainly within the first month after delivery. Breast feeding education should focus on supportive care to mothers practicing mixed feeding.

• Journal of Korean Society of Transportation
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• v.30 no.4
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• pp.21-32
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• 2012

Exclusive bus lane (EBL) is typically located in the roadway median, and is accessed by weaving across the GPLs(general purpose lanes) before entering from the left lane of the GPLs. To maximize the potential for successful EBL operations, a critical design issue that requires special attention is the length of bus weaving section before entering EBL. The process of developing guidelines for the length of bus weaving section can be supported by a sensitivity analysis of performance measure (safety) with respect to the bus weaving distance. However, field data are difficult to obtain due to inherent complexity in creating performance measure (safety) samples under various interesting flows and bus weaving distance that are keys to research success. In this paper, VISSIM simulation is applied to simulate the operation of roadway weaving areas with EBL, and based on vehicle trajectory data from microscopic traffic simulation models, the Surrogate Safety Assessment Model (SSAM) computes the number of surrogate conflicts (or degree of safety) with respect to the bus weaving distance. Then, a multiple linear regression (MLR) model using safety data (number of surrogate conflicts) is developed. Finally, guidelines for bus weaving distance are established based on the developed MLR. Developed guidelines explicitly indicate that a longer bus weaving distance is required to maintain desired safety as weaving volume increases.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.230-240
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• 2018

The objective of this study is to observe the exclusive breastfeeding(EBF) rate and to identify factors which influence EBF by postpartum period. The data were obtained from the 2015 National Fertility Survey, Family Health and Welfare in Korea, and secondary data analysis were employed for 1,839 mothers who gave birth to baby between January 2013 and February 2015. Data were analyzed using SPSS 25.0 program with descriptive statistics, chi-square test and multiple logistic regression. The EBF rate at the 1st and 6th month of postpartum were 54.0%, 9.4% respectively. The significant influencing factors on the EBF at the 1st month of postpartum were age of mother, baby's birth rank, type of delivery, breastfeeding within 1 hour after delivery. The significant influencing factors on the EBF at the 6th month of postpartum were age of mother, living area, EBF in the first month. We found that the influencing factors on EBF differed by postpartum period. In order to improving the rate of EBF, it is recommended that taioed interventions is needed considering the factors affecting the EBF by postpartum period.

• Journal of Korea Port Economic Association
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• v.26 no.3
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• pp.114-129
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• 2010

Busan port's main function is handling container cargo compared to world major ports and the percentage of handling general cargo such as dirty bulk cargo is very low. In other words, although total cargo weight of Busan port that recorded the handling result of 13.29million TEU in 2008 reached 113.05million ton, total cargo weight of general cargo was 15.31million ton, so container cargo accounted for 88.1% of whole cargo weight. However, it is the time to create high added value by the increase of handling and marketing dirty bulk cargo. Originally, the dirty bulk cargo was not the avoided object from the first. Somehow, it is a very high added value cargo, and is surely essential strategic material to basic industries of nation. However, it becomes dirty bulk cargo as the companies are reluctant to handle it because of environmental problem, distinct characteristic in handling, uncertain break even point due to imbalance between supply and demand compared to container cargo. However, items that are classified as dirty bulk cargo now are certainly necessary strategic materials to national basic industries or national life. Besides it seems to be a high added value cargo here and now. Therefore, it is time that increasing of handling dirty bulk cargo by marketing it and the system for efficient handling such as constructing the exclusive use wharf in Busan port, modernizing of facilities and equipments, stable secure of place for holding and handling through development of distribution complex by item, efficient data processing and closer cooperation by setting up a SCM of related authorities are needful.

• Clean Technology
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• v.26 no.1
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• pp.39-54
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• 2020

This study analyzed the groundwater quality according to the depth and geological features in Gyeongsangnam-do area using groundwater quality monitoring network data to grasp the groundwater quality characteristics and to provide basic data for policy making on efficient groundwater management. Five hundred and three data sets were acquired from background water quality exclusive monitoring network in soil groundwater information system for five years (2013 ~ 2017). Except for the total coliforms and tracer items such as mercury, phenol, and others, the parameters of water quality were significant or very significant, depending on depth and geological features. As the depth got deeper, the average value of pH and electrical conductivity increased; water temperature, dissolved oxygen, oxide reduction potential, arsenic, total coliforms, and turbidity decreased; and total unfit rate for drinking water standards was lower. It was found that the sum of the positive and negative ions was the highest in the clastic sedimentary rock and the lowest in metamorphic rock. The total unfit rate for drinking water standards was the highest for metamorphic rocks, followed by clastic sedimentary rock and unconsolidated sediments and, finally, intrusive igneous rock with the lowest penetration. The Na-Cl water type, which indicated the possibility of contamination by external pollutants, appeared only at some points in shallow depths and in clastic sedimentary rocks.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.4
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• pp.542-553
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• 2018

Since many previous studies reported the health effect of air pollution and indicated traffic as a major pollution source, significant policy efforts have been made to control traffic to reduce air pollution. However, there have been few studies that evaluated such policy implementation. In Seoul, Korea, the exclusive median bus lane system was implemented in 2004, and the metropolitan government applied air pollution reduction policies such as conversion of diesel buses to compressed natural gas buses and installation of emission control devices. This paper aimed to investigate the impact of the exclusive median bus lane system on air pollution reduction. Using hourly concentrations of particulate matter ($PM_{10}$) and nitrogen dioxide ($NO_2$) measured at 131 regulatory monitoring sites in Seoul and Gyeonggi-do for 2001-2014, we calculated annual and daily average concentrations at each site. We assessed the impact of the policy using differences-in-differences analysis by annual and daily average models after adjusting for geographic and/or meteorological variables. This method divides population into treatment and control groups with and without policy application, and compares the difference between the two time periods before and after the policy implementation in the treatment group with the difference in the control group. We classified all monitoring sites into treatment and control groups using two definitions: 1) Seoul vs. Gyeonggi-do; 2) within vs. outside 300 meters from the median bus lane. Pre- and post-policy periods were defined as 2001-2005 and 2006-2014, and 2004 and 2014 in the annual and daily models, respectively. The decrease in $PM_{10}$ concentrations between the two periods across monitoring sites in the treatment group was larger by $1.73-5.88{\mu}g/m^3$ than in the control group. $NO_2$ also showed the decrease without statistical significance. Our findings suggest that an efficient public transport policy combined with pollution abatement policies can contribute to reduction in air pollution.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.2
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• pp.139-145
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• 2017

Recently, gusts, typhoon and tsunamis have been occurring more frequently around the world. In such an emergency situation, a moored vessel can be used to predict and analyze other vessel behavior, but if the mooring system is destroyed, marine casualties can occur. Therefore, it is necessary to determine quantitatively whether a vessel should be kept in the harbour or evacuate. In this study, moored ship safety in an exclusive wharf according to swell effects on motion and mooring load have been investigated using numerical simulations. The maximum tension exerted on mooring lines exceeded the Safety Working Load for intervals 12 and 15 seconds. The maximum bollard force also exceeded 35 tons (allowable force) in all evaluation cases. The surge motion criteria result for safe working conditions exceeded 3 meters more than the wave period 12 seconds with a wind speed of 25 knots. As a result, a risk rating matrix (risk category- very high risk, high risk and moderate risk) was developed with reference to major external forces such as wind force, wave height and wave periods to provide criteria for determining the control of capabilities of mooring systems to prevent accidents.

• Journal of Technologic Dentistry
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• v.38 no.4
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• pp.281-290
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• 2016

Purpose: The increased aesthetic requirements and demands of patients have resulted in the developments of coloring liquid for zirconia. Methods: In this study, zirconia block was dipped into $Fe(NO_3)_3$solution, which showed a color and then concentration of $Fe(NO_3)_3$and zirconia's color and physical properties depending on the dipping time were observed and compared with exclusive coloring solutions. As the result, the following conclusions were obtained. Results: When compared with the specimens that were colored using exclusive solutions, $L^*$ value rose overall depending on the concentration of $Fe(NO_3)_3$and $a^*$ value was red in the form of (+) in all the specimens. Also, $b^*$ value was in the form of (+) at 0.5 to $1{\ss}fl$, but was in the form of (-) at 1.5 to $2{\ss}fl$. The dipping time did not highly influence $L^*$ value, but $a^*$ value and $b^*$ value were directly opposite to the specimens, which were not colored, except the sample that was dipped for only 2 seconds. When compared with exclusive coloring solutions, $Fe(NO_3)_3$had the most similar color at 0.5 to $1{\ss}fl$ and the longer the coloring time, the higher the rate of color change became. In relation to the density change depending on the addition of $Fe(NO_3)_3$, there was the lowest density at $2{\ss}fl$ and the density was increased in the specimens that were not colored. Conclusion: These results show that $Fe(NO_3)_3$solution can be used to make colored zirconia. It is expected that newly made colored zirconia can be used in clinical practice because the colored zirconia not only possesses the mechanical properties that all ceramic core material should have but also was biocompatible to a living cells.

• Journal of Korean Port Research
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• v.7 no.1
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• pp.43-58
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• 1993

There has been fast progress in economy in Korea derived by a consecutive five-year plan program for economic development started in the early 1960's. In the field of transportation, rapid changes in the technological environment of transportation and communication have brought a revolution of the transport system, of which inter-modal transportation through containerisation is typical. Because of the rapidly growing traffic volumes of cargo, especially container traffic, and lack of investment into transport infrastructure in the past, both road and railway are beyond their capacity. As a result, the public-road network has suffered a serious congestion problem. For instance, in relation to the corridor between Seoul and Pusan, today, it takes about 14 hours for the journey of container trailer through Kyongbu Expressway, for which it used to take only 7 hours in 1986. For the railway, though the congestion problem is not very serious compared with the road sector, a shortage of capacity on certain main lines has emerged as a problem as railway traffic has increased. Furthermore, the further expansion of the system in near future is difficult due to burden of higher construction the cost. Unlike these two modes, coastal shipping, which has been paid relatively less attention for commodity transport in Korea, shows no constraint in this respect. In addition, it is the most cost efficient mode of transport. This work therefore aims to make a proposal for the alternative inland transportation mode, which is to promote the coastal transport of container. Three obstructing factors for the promotion of the coastal transport are investigated and some solutions for those are suggested as follows : First, it appears to be essential to provide exclusive ports for the coastal shipping, that comply with simplification, specialization and rationalization. The optimum size of berths on the exclusive ports in Pusan port is estimated as 16-20. We found that it needs periodical study and publicity on the advantages from the adoption of the coastal mode. Inducing competition in the coastal shipping market is also necessary. For the supply of the fleet in the coastal shipping, chartering of the surplus ships in the oversea shipping is found to be more desirable than new shipbuilding. Second, to solve the fragmentation of the companies which wish to participate in the coastal transport, government has to implement the subsidy policy. The encouragement of participation of the shipping lines engaging in Korea-Japan run and Korea-East South Asia run, into coastal shipping also needs to be considered cautiously. Third, simplification of the document for entry in ports is needed for rational coastal shipping management. We can use B/L (Bill of Lading) for coastal shipping as a prerequisite to get the indemnity by P & I Club. The reduction of the government controls on entering and leaving the ports also needs.

• (The)Study of the Eastern Classic
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• no.69
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• pp.419-450
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• 2017

This study aims to discover the clue of the current modern postal system development by looking at the delivery patterns of Korean letters during the Joseon Dynasty. A letter is a text medium that the sender sends to a recipient by sending a message of news. The form and contents of the letter are influenced by the various surrounding factors and are adapted to circumstances. The study aims to clear up the method of delivery and the nature of the transmitter among the environmental factors which affects the format and contents of Korean letters. Depending on the public or private matters, the delivery method is divided into a public agency and a private messenger, or divided into one-phase delivery and the multi-phase delivery depending on whether or not a phase is divided into stages. It is also divided into a one-way and a round-transmission depending on whether or not it is round-switched. The transmitter is divided into a verbal communication, the letter and verbal communication, and the letter communication according to whether or not it is by verbal, and divided into the relational and the non-relational person according to the relationship with the sender. Also depending on whether the transmitter is exclusive or not, it is divided into the exclusive messenger and the messenger who deliver a letter incidentally while come and go. In the aspect of the delivery method, We can see the possibility of developing to a modern mail system through the public method, the multi-phase delivery, one-way delivery and in the aspect of the transmitter, we can see the possibility through the letter delivery, non-related transmitter, and the exclusive messenger.