• Journal of KIISE:Information Networking
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• v.37 no.3
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• pp.167-174
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• 2010

Recently the distributed topology control algorithm for constructing the Recrystallization Topology in the unstructured peer-to-peer network was proposed. In this paper, we prove that such a hierarchical topology is a scale-free power-law network. We present a model of a construction process of the distributed protocol, and analyze it based on a mean-field approximation and the continuum theory, so that we show that the constructed Recrystallization Topology is a scale-free network. In the proposed model, all nodes are born with some initial attractiveness and the system incorporates the rewiring of some links at every time step. Some old links are removed with the anti-preferential probability, and some new links are added with preferential probability. In other words, according to the distributed algorithm, each node makes connections to the more-preferential nodes having higher hit-ratio than other nodes, while it disconnects the anti-preferential nodes having lesser hit-ratio. This gives a realistic description of the local processes forming the recrystallization topology in unstructured peer-to-peer network. We calculate analytically the degree distribution. The analytic result indicates that the constructed network is a scale-free network, of which the scaling exponent is 3.

• Membrane Journal
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• v.23 no.3
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• pp.226-236
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• 2013

The effect of $N_2$ back-flushing period (FT) and time (BT) was compared with the previous result used PES (polyethersulfone) beads loaded with titanium dioxide photocatalyst in hybrid process of alumina microfiltration and PP (polypropylene) beads coated with photocatalyst in viewpoints of membrane fouling resistance ($R_f$), permeate flux (J), and total permeate volume ($V_T$). The reason of nitrogen back-washing instead of the general air back-washing method is to minimize the possible effect of oxygen included in air on water quality analysis. As decreasing FT, $R_f$ decreased and J and $V_T$ increased. Treatment efficiency of dissolved organic matters (DOM) was 82.0%, which was the higher than 78.0% of the PES beads result. This means that PP beads coated with photocatalyst was the more effective than PES beads loaded with photo-catalyst in the DOM removal. As increasing BT, the final $R_f$ decreased and the final J increased, but $V_T$ was the maximum at BT 15 sec. The average treatment efficiency of turbidity did not have any trend as changing BT. As BT increasing from 6 sec to 30 sec, the treatment efficiency of DOM increased 11.8%, which was a little higher than the result of PES beads.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.380-388
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• 2016

This study suggests methods to evaluate the availability of anchorage in Ulsan port and determine the proper capacity of future anchorage in accordance with port development. Accordingly, the concept of an Anchorage Operating Rate (AOR) is introduced to evaluate the capacity of anchorage that was available in Ulsan port in 2014. Calculations revealed that the operating rate of all anchorages in Ulsan port did not exceed 100 %. However, in 2020 it is estimated that the AOR at E1 anchorage will be the highest with a rate of 168.3 %, followed by E3 with 131.1 %, E2 with 118.5 % and M with 108.7%. These findings indicate a shortage of anchorage by 2020. In order to decrease the AOR to a level that will not exceed 100 %, in accordance with port development in Ulsan, areas to accommodate an additional 11 ships at E1 anchorage, 1 ship at E2 anchorage, 2 ships at E3 anchorage and 1 ship at M anchorage will be necessary.

• Membrane Journal
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• v.18 no.1
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• pp.7-25
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• 2008

Sodium dodecyl sulfate, which was anionic surfactant, at a concentration higher than its critical micellar concentration was added to calcium solution for forming micelles. Then aggregates were formed by adsorption or binding of calcium ions on the surface of micelles, and gathering between them, and then rejected by two kinds of ceramic membranes to remove calcium ions. As result, rejection rates of calcium were higher than 99.98%. And in our experimental range the higher TMP trended to increase the resistance of membrane fouling ($R_f$), total permeate volume ($V_T$), dimensionless permeate flux ($J/J_o$) and permeate flux (J) because TMP was driving force. And we investigated effects of $N_2$-back-flushing time and filtration time, that was back-flushing period, during periodic $N_2$-back-flushing on ceramic membranes. As result, optimal BTs for NCMT-623l ($0.07{\mu}m$ pore size) and NCMT-7231 membrane ($0.10{\mu}m$) were 10 sec and 15 sec, respectively. Also, optimal FT was 5 min for both membranes, and the frequent $N_2$-back-flushing could decrease membrane fouling effectively. Then, the optimal conditions resulting from our experiments for synthetic calcium solution were applied to groundwater using as washing process of soymilk package. As result, rejection rates of calcium were higher than 99.98%.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.307-314
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• 2020

This purpose of the study is to investigate the influence of perception of importance of communication, self-esteem and communication skill on patient safety attitude of nursing students. Subjects were 164 associate nursing students associate nursing students(3·4rd). The data were collected using self -report questionnaire from May 17 to June 14, 2019. Data were analyzed by descriptive statistics, t-test, ANOVA, Pearson correlation and hierarchical multiple regression with SPSS/WIN 23.0. Mean point of perception of importance of communication(5 point scale) was 3.75. self-esteem(4 point scale) was 3.64, and communication skill(5 point scale) was 3.60 and patient safety attitude(5 point scale) was 4.44. Patient safety attitude were positively correlated with perception of importance of communication (r=.57, p<.001), self-esteem(r=.32. p <.001) and communication skill(r=.34. p <.001) of nursing students. Perception of importance of communication(β=.520, p<.001), self-esteem(β=.165, p=.039) explained 34.76% of total variance of patient safety attitude of nursing students. Therefore, To increase patient safety attitude of nursing students, it is necessary to develop and test the program for improving perception of importance of communication and self-esteem of nursing students.

• Journal of Hospice and Palliative Care
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• v.16 no.2
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• pp.108-117
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• 2013

Purpose: The objectives of this study were to 1) explore nurses' attitudes toward death, coping with death, understanding and performance regarding end-of-life (EOL) care, 2) describe correlations among the above factors, and 3) determine the factors affecting nurses' EOL care performance. Methods: Study participants were 187 nurses stationed at departments that post higher mortality than others such as the oncology department, intensive care unit (ICU) and emergency department (ED). Data were collected from three urban university-affiliated hospitals. Multi-dimensional measure was performed for study instruments such as "attitude toward death", "coping with death" and "understanding and performance regarding EOL care". Data were analyzed by using descriptive statistics, correlation, and multiple regressions. Results: First, nurses showed significantly different attitudes toward death by age, religion, work unit and EOL care education. Younger nurses tend to score low on the understanding of EOL care, and ED nurses' score was lower than their peers at the oncology department and ICU. Second, EOL care performance was positively correlated with attitude toward death (P<0.001), coping with death (P=0.003) and understanding of EOL care (P<0.001). Third, nurses' EOL care performance was affected by work unit (P<0.001) and understanding of EOL care (P<0.001). Conclusion: Because nurses' performance was influenced by their work unit and understanding of EOL care, they should be provided with appropriate training to improve their understanding of death and EOL care according to work unit.

• Korean Journal of Childcare and Education
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• v.7 no.2
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• pp.159-180
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• 2011

This study examined the effects of children's temperament, self-control and maternal parenting on children's playfulness. The subjects of this study were 288 3-, 4- and 5- years old children and their mothers. The collected data were analyzed by correlations and pathway analysis. The results were as follows: First, children's sex, sociability temperament, self-control and maternal authoritarian parenting directly affected children's playfulness. Children's sex indirectly affected children's playfulness through children's activity level and self-control. Children's sociability and emotionality temperament indirectly affected children's playfulness through maternal authoritarian parenting. Maternal authoritarian parenting indirectly children's playfulness affected through children's self-control. Second, the most important variable predicting children's playfulness was maternal authoritarian parenting.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.245-252
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• 2016

This study investigated the environmental conditions and planktonic organisms in the ballast waters (BW) of 22 vessels originating from the international ports of Japan for the purpose of negotiating exemptions from the Ballast Water Management Convention (BWM Convention). The shortest duration of the BW was $3.33{\pm}1.87days$ in area "A", which included Kyushu and Suo Nada at Seto Inland. The total suspended solids, dissolved organic carbon, and particulate organic carbon ranged from 4.60 to 60.9 mg L-1, from 0.97 to 2.69 mg L-1, and from 0.24 to 4.51 mg L-1, respectively. A low average concentration of nutrients was measured in the BW from area "A", but that in the BW from area "C" (around central Honshu) was high, which may be related to the ballasting periods. High chlorophyll-a concentrations (>$1{\mu}g\;L-1$) were measured in four vessels, three of which carried the BW in area "A". High abundances of phytoplankton (> 50,000 cells L-1) were measured in four vessels, three of which carried the BW in area "A". The two vessels originating from Tokyuyama Bay in area "A" showed high densities of dinoflagellates, which are known to be harmful algae. Our results suggest that the negotiations for an exemption from the BWM Convention for Japan should proceed with caution.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.663-670
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• 2014

The Pyeongtaek port is expected lack of waiting anchorage due to increase of incoming ships whit increasing of trading volume in the near future. In case of an anchorage facility's structural alternations and expansion, it should be considered comprehensively how it affects other anchorage facilities. In addition, the volume of ship traffic to relevant area should be estimated accurately and then the facility's scale is calculated. In this paper, researchers calculated cargo per unit ship with the throughput for every ship and predicted the number of ships which had entered Pyeongtaek port. As a result, the port's ability to be docked was predicted to be not enough in 2030. It will exceed the number of ships able to cast anchor at specific two parts simultaneously 12.6 and 1.6 respectively consequently, the necessity to expand the ports was suggested. Hence, the best expansion plan was examined with analysis of marine transportation environment at each ports and the improvements suggested are anchoring ships at Ippado anchorage is 19.7 and the one at Janganseo anchorage is 12.6.

• Journal of Convergence for Information Technology
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• v.8 no.3
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• pp.183-191
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• 2018

This study is to examine the effects of Socially Prescribed Perfectionism on depression by Intolerance of Uncertainty and Unconditional Self Acceptance, and to well being to improve the positive life of college students. This study is conducted on 238 college students who are influenced by Socially Prescribed Perfectionism, Intolerance of Uncertainty, Unconditional Self Acceptance, and Depression. This study analyzed a questionnaire consisted of a sub-component of the Multidimensional Perfectionism Scale (MPS), a Intolerance of Uncertainty Scale(IUS), an Unconditional Self Acceptance Questionnaire-R(USAQ-R), and a depression scale (CES-D) and verified correlation analysis and structural equation model. The results of this study showed that socially prescribed perfectionism had significant negative correlations with intolerance of uncertainty, and had significant positive correlation with unconditional self acceptance. The results of the structural equation model showed full mediating effect of the intolerance of uncertainty and unconditional self acceptance between Socially prescribed perfectionism and depression, Finally, implications and suggestions are suggested in this study.