• Advances in materials Research
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• v.5 no.2
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• pp.67-80
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• 2016

The objective of the present work is to optimize process parameters namely, cutting speed, feed rate, and depth of cut in milling of AISI 304 stainless steel. In this work, experiments were carried out as per the Taguchi experimental design and an $L_{27}$ orthogonal array was used to study the influence of various combinations of process parameters on surface roughness (Ra) and material removal rate (MRR). As a dynamic approach, the multiple response optimization was carried out using grey relational analysis (GRA) and desirability function analysis (DFA) for simultaneous evaluation. These two methods are considered in optimization, as both are multiple criteria evaluation and not much complicated. The optimum process parameters found to be cutting speed at 63 m/min, feed rate at 600 mm/min, and depth of cut at 0.8 mm. Analysis of variance (ANOVA) was employed to classify the significant parameters affecting the responses. The results indicate that depth of cut is the most significant parameter affecting multiple response characteristics of GFRP composites followed by feed rate and cutting speed. The experimental results for the optimal setting show that there is considerable improvement in the process.

• Explosives and Blasting
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• v.36 no.1
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• pp.1-11
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• 2018

In this study, several underwater steel cutting tests and AUTODYN numerical analyses were conducted to evaluate the penetration performance of a shaped charge device. Parameter analyses for the contribution rate were conducted by using the robust design method. The parameters adopted in this study were chamber type, stand-off, and wire setting, each of which had three levels in the analysis. Analysis results showed that the contribution rate was most affected by the stand-off, followed by the chamber type and wire setting. Experiments of underwater steel cutting were conducted at water depth of 25m. As expected, the experiments and numerical simulation showed similar results for underwater steel cutting performance, and thus the feasibility of the shaped charge device for underwater steel cutting at deep water depth was verified.

• Journal of the Korea Concrete Institute
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• v.17 no.5 s.89
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• pp.703-708
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• 2005

The effects of polymer-cement ratio and antifoamer content on the setting time and durability of high-fluidity polymer-modified mortars using redispersible polymer powder are examined. As the result, the setting time of the polymer-modified mortars using redispersible polymer powder tends to be delayed with increasing polymer-cement ratio, regardless of the antifoamer content. The water absorption, chloride ion penetration depth and carbonation depth of the high-fluidity polymer-modified mortars using redispersible polymer powder decrease with increasing polymer-cement ratio and antifoamer content. The resistance of freezing and thawing and chemicals improvement is attributed to the improved bond between cement hydrates and aggregates because of the incorporation of redispersible polymer powder

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.10
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• pp.83-94
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• 2018

In many theoretical and empirical studies on the design issues of therapeutic healthcare facilities, spatial configuration that promotes users' wayfinding behavior, has been emphasized as a significant factor to mitigate stressful experiences and to enhance restorative quality in the healthcare environment. This is also applicable to the healthcare setting for children. However, not much evidence has been reported with regard to the relationship between spatial configuration and wayfinding behaviors in this specific setting. Moreover, healthcare facilities for children with physical disabilities need more attention to provide easy wayfinding due to various physical restrictions. The aim of this study is therefore, to unfold the relationship between spatial configuration and visual cognitive qualities of outpatient spaces in the selected children's rehabilitation hospitals in Seoul, by examining visual cognitive attributes such as visibility, accessibility, and intelligibility. In the first phase, the spatial layout of the hospitals was analyzed, with an emphasis on the major outpatient areas such as the entrance lobby, doctors' examination, and physical therapy zones. In the second phase, a space syntax tool was implemented to examine visual cognitive characteristics of the spatial configuration. The spatial configuration parameters measured were integration, integration core, visual isovist field continuity, correlation between integration and step depth, and the correlation between integration n and integration 3. As a result, the integration was higher in the hall type configuration. Circulation intersections acted mostly as integration cores for better visibility. Some areas showed the lack of continuity in the visual isovist fields overlap and irregular correlation between integration and step depth. The intelligibility was higher in the circulation area and social interaction spaces such as a cafe, reception waiting, and therapy waiting areas. Based on the analysis, design implication and possible future improvement were discussed to enhance wayfinding experiences in the hospitals for children with physical disabilities.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.1
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• pp.54-59
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• 2000

This paper presents a control system that uses a fuzzy algorithm in controlling the depth of a model midwater trawl net, and experimental results carried out in the circulating water channel by using a model trawl winch system.The fuzzy controller calculates the length of the warp to be changed, based on the depth error between the desired depth and actual depth of the model trawl net and the ratio of change in the depth error. The error and the error change are calculated every sampling time. Then the control input, i.e. desirable length of the warp, is determined by inference from the linguistic control rules which an experienced captain or navigator uses in controlling the depth of the trawl winch controller and the length of the warp is changed. Two kinds of fuzzy control rules were tested, one was obtained from the actual operations used by a skilled skipper or navigator, and the other was a modified from the former by considering the hydrodynamic characteristics of the model trawl system.Two kinds of fuzzy control were tested, one was obtained fro the actual operations used by a skilled skipper or navigator, and the other was a modified from the former by considering the hydrodynamic characteristics of the model trawl system.The results of these model experiments indicate that the proposed fuzzy controllers rapidly follow the desired depth without steady-state error although the desired depth was given in one step, and show robustness properties against changes in the parameters such as the change of the towing sped. Especially, a modified rule shows smaller depth fluctuations and faster setting times than those obtained by a field oriented rule.

• Radiation Oncology Journal
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• v.7 no.2
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• pp.279-285
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• 1989

Central axis depth dose data for 6 MV X-rays, including tissue maximum ratios, were measured for wedge fields according to Tatcher's equation. In wedge fields, the differences in magnitude which increased with depth, field size, and wedge thickness increased when compared with the corresponding open field data. However, phantom scatter correction factors for wedge fields differed less than $1\%$ from the corresponding open field factors. The differences in central axis percent depth dose between two types of fields indicated beam hardening by the wedge filter The deviation of percent depth doses and scatter correction factors between the effective wedge field and the nominal wedge field at same angle was negligible. The differences were less than $3.20\%$ between the nominal or effective wedge fields and the open fields for percent depth doses to the depth 7cm in $6cm{\times}6cm$ field. For larger $(10cm{\times}10cm)$ field size, however, the deviation of percnet depth doses between the nominal or effective wedge fields and the open fields were greater-dosimetric errors were $3.56\%$ at depth 7cm and nearly $5.30\%$ at 12cm. We suggest that the percent depth doses of individual wedge and wedge transmission factors should be considered for the dose calculation or monitor setting in the treatment of deep seated tumor.

• Journal of Information Technology Applications and Management
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• v.18 no.4
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• pp.149-168
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• 2011

The current study initiated from an action-plan level perspective of revitalizing Green IT (Information Technology) in Korea by building a standardized national Green IT brand. In order to setting up a national level brand, there should be a big quantitative survey for identifying Green IT brand concepts. For this, the current study provides exploratory research results based on preliminary interviews and literature survey before the quantitative survey. The present article suggests a research framework and describes important factors for setting up a national level Green IT brand. In-depth interviews with panels were executed and existing Green IT brands in other countries are summarized and asked for evaluation to a small number of panels. The research results show that (1) National level Green IT brand should include wider concepts of IT, (2) Green IT brand will be more appealed by the public when it is simple, straightforward, and intuitive, (3) Earth, Tree, and/or Water show higher correlation with Green IT concepts. Green IT brand will offer marketing promotion effects to companies who adopt national level Green IT brand as well as increase public use of Green IT in daily life. For this reason, Green IT brand will be a win-win strategy and this should be cared and executed by the related government agencies with long term perspective.

• Journal of Korean Academy of Nursing Administration
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• v.13 no.4
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• pp.526-536
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• 2007

Purpose: The purpose of this phenomenological research was to identify nurses's experience of verbal violence from doctor in hospital setting. Methods: The participants of this study were twelve nurses who work at a hospital in Chungbuk. Data was collected through documents, observation, and tape-recorded in-depth interview individually from participants. It was analyzed using the phenomenological methodology by Colaizzi. Results: From significant statements, seven categories were identified as follows: Lowering self-esteem due to authoritative and insulting remarks, Getting angry and being disagreeable due to blunt remarks, Being disgraceful due to broad jokes sexually, Hoping to escape present due to skepticism in their job, Being estranged due to bad feeling, Expressing their anger, and Using various way for improvement of relationship. Conclusion: Nurses's experience of verbal violence was showed nurse-doctor relationship was still vertical, not collaborative and supportive. This vertical relationship would cause conflicts between doctor and nurse. Therefore it is need doctor to be changed the mind that nurse is a professional, and to come up with the plan for enhancing inter-collaborative relationship in order to solve conflict between them.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.3 no.1
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• pp.128-140
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• 1996

This study is to understand and to explain how nursing students experience in the clinical nursing practice using grounded theory approach. Ten nursing students were participated in the study. Seven of them were junior students at the junior college of nursing, and the rest were the senior students at the university. The data were collected by in-depth individual interviews by investigators during May and June in 1995. The results of the study were as follows ; Twenty-eight concepts and 9 categories were emerged by the constant comparative analysis. The 9 categories include 'the need of role model', 'non-educational practical setting', 'knowledge deficit', 'emotional changes', 'the attitudes of clinical practice', 'fatigue', 'skepticism', 'pride', and 'the product of clinical practice'. The core category which encompasses all 9 categories was emerged as 'the process of formulating the nursing view'. Five hypotheses were derived from the analysis. 1) The desirable role model would enhance to pride of nursing in students. 2) Non-educational practical setting would increase skepticism of nursing in students. 3) Knowledge deficit would negatively affect on experience of clinical practice. 4) The pride of clinical practice would formulate a positive nursing view. 5) The skepticism of clinical practice would formulate a negative nursing view. The results of this study are to use as basic data for students attending clinical experience.

• Perspectives in Nursing Science
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• v.10 no.1
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• pp.1-11
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• 2013

Purpose: Given the importance and impact of trust between nurse and pediatric patient on treatment adherence and nursing outcomes, this study was aimed to investigate how nurses perceive the trust between nurses themselves and children in a hospital setting using a qualitative research methodology. Methods: In depth interviews with 10 nurses working at pediatric units were conducted using semi-structured questionnaires, and data were analyzed using a thematic analysis. Results: Main themes were categorized as attributes of nurse-child trust and influencing factors. Attributes of trust can be divided into definition and characteristics of nurse-child trust. Nurses perceived nurse-child trust were not coercive, and changeable mutual relationship needing time and effort, and helpful for child's hospital adaptation and child's participation for care. There existed facilitating factors and interfering factors in developing nurse-child trust. Conclusion: The findings of this study would help nurses who are caring children in a hospital setting re-shape their points of views on 'trust between nurses and children' in day to day practice. It is also hoped that these results contribute to develop nursing guidelines on trust building with children in hospital in future.