• Journal of the Korean Ceramic Society
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• v.41 no.4
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• pp.302-312
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• 2004

This paper presents the experimental results on the properties of the cement mortar with polycarboxylate-type superplasticizers PCA) which were synthesized by different mole ratio of methoxypoly(ethyleneglycol)monomethacrylate (MPEGMAA) and methacrylic acid (MAA) and by different length of polyethyleneoxide (PEO). As the PEO chain was longer and mole ratio of [MPEGMAA]/[MAA] was lower, the fluidity of cement mortar was better. The setting time of mortar with PCA was retarded, and as PEO chain was shorter and [MPEGMAA]/[MAA] was lower, it was more retared. Espeacially, when the molecular weight of MPEGMAA was 475(repeat unit of ethylene oxide=l0), the degree of retardation was the highest of them. The surface tensions of PCA solutions were lower than that of water due to the effect of PEO chain, and also the pore size distribution of cement mortar was influenced by it. The pores in cement mortar with PCA at 28 days were macropores in the range of 7 to 370$\mu\textrm{m}$, and accordingly, the densities and compressive strengths of mortar were lower than those of OPC mortar.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.204-204
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• 1999

The plasma source ion implantation(PSII) technique which is a method using high negative voltage pulse in plasma system has the potential to change the surface properties of polymer. PSII technique increase the surface free energy by introducing polar functional groups on the surface so that it improves reactivity, hydrophilicity, adhension, biocompatability, etc. However, the mobility of polymer chains enables the modified surface layers to adapt their composition to interfacial force. This hydrophobic recovery interrupts the stability of modified surfaces to keep for the long time. In this study, poly(methyl methacrylate)(PMMA), poly(2-hydroxyethyl methacrylate)(PHEMA), and polu(2-hydroxypropyl methacylate)(PHPMA) for contact lens application, were modified to improve the wettability with PSII technique and were investigated the surface stabilities. Polymer film was prepared with solution casting(3 wt.% solution) and was annealed at 11$0^{\circ}C$ under vacuum oven to remove solvent completely and to eliminate physical ageing. The thickness of the film measured by scanning electron microscopy (SEM) and surface profilometer was about 10${\mu}{\textrm}{m}$. Polymers were treated with different kinds of gases, pulse frequency, pulse with, pulse voltage, and treatment time. Even though PMMA, PHEMA, and PHPMA have similar repeat unit structure, the optimal treatment conditions and the tendency to hydrophobic recovery were different. PHPMA, more hydrophilic polymer than PMMA and PHEMA showd better wettability and stability after mild treatment. Surface tensions were obtained by water and diiodomethane contact angle measurements to monitor the relation between hydrophobic recovery and polymer structure. Different ion species in plasma change the polar component and dispersion component of polymer surface. For better wettability surface, the increase of polar component was a dominant factor. We also characterized modified polymer surfaces using x-ray photoelectron spectroscopy(XPS), secondary ion mass spectrometry(SIMS), Fourier Transform infrared spectroscopy(FT-IR), and SEM.

• Fashion & Textile Research Journal
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• v.16 no.5
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• pp.680-688
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• 2014

The aim of this research is to classify intrinsic attribution of 'la diff$\acute{e}$rance images' which are core propositions of changeability of fashion style. The specific questions of this research are; what are the definition of 'changeability of fashion', 'la diff$\acute{e}$rance' and 'supplement' and what are the relationships?, how the la diff$\acute{e}$rance images which are intrinsic of changeability of fashion style exist? and what is intrinsic attribution of 'ultimate la diff$\acute{e}$rant image', 'immediate la diff$\acute{e}$rant image' and 'la diff$\acute{e}$rant image of the trace'? The researchers deployed a qualitative research method providing a systematic review of the previous studies. In conclusion, the 'supplement' phenomenon and 'la diff$\acute{e}$rant images' shown in the changeability of fashion style, covers up the gap between the structural layers through the play led by supplement logic in the subconscious place of la diff$\acute{e}$rance of dialectical frame. They produce styles that have current value and become generalized la diff$\acute{e}$rant images of trace through the play of 'la dissemination.' These images repeat their individual play to reproduce a new different 'la diff$\acute{e}$rant images' and complete the aesthetics of harmony in the state of 'reservation,' 'deferment' and 'postponement'. The images are ready to make history and they create 'ultimate la diff$\acute{e}$rant images' from the demand of different period, and tries to combine with 'supplement' within 'the gap of la diff$\acute{e}$rance.' This process endlessly repeats in the dialectical frame through the la diff$\acute{e}$rant' play led by time and space, and it continuously produces new style that is required by different time and space.

• International Commerce and Information Review
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• v.9 no.2
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• pp.103-120
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• 2007

The knowledge based economy requires more and more people to learn new knowledge and skills in a timely and effective manner. These needs and new technology such as computer and Internet are fueling a transition in e-learning. According to specialist's opinion, imagination experience studying is generalized, and learning environment that language barrier by studying, multi-language studying Machine that experience past things that disappear through simulation, and travel area, and experience future changed state disappears is forecasting to come. This is previewing finally that it may become future education that education and IT, element of entertainment is combined. Already, became story that argument for party satellite of e-Learning existence passes one season already. e-Learning is utilized already in all educations that we touch by effectiveness by corporation's competitive power improvement and implement of lifelong education in educational institutions through present e-Learning. It is obvious that when see from our viewpoint which is defining e-Learning by one industry and rear by application to education as well as one new growth power about these, e-Learning industry becomes very important means that can solve dilemma of growth real form. Only, special quality of digital industry that e-Learning is being same with other digital industry and repeat putting out a fire rapidly, and is repeating sudden change that these evolution is not gradual growth of accumulation and improvement of technology that is appearing consider need to. In the meantime, we need to observe about evolution of Information Technology. Because there is some scholars who e-Learning's concept foresees to evolve by u-Learning.(although, a person who see that these concept is not more in marketing terminology by some scholars' opinion is). This u-Learning's concept means e-Learning that take advantage of ubiquitous technology as Ubiquitous-Learning's curtailment speech. Ubiquitous, user means Information-Communication surrounding that can connect to network freely regardless of place without feeling network or computer. There is controversy about introduction time regarding these direction, but e-Learning is judged to evolve by u-Learning necessarily. Because keep in step and age that study all contents that learner wants under environment of 3A (any time, any whrer, any device) by individual order thoroughly is foreseen to come in ubiquitous learning environment that approach more festinately.

• Journal of Chest Surgery
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• v.45 no.4
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• pp.225-229
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• 2012

Background: Reoperation of cardiac surgery via median sternotomy can be associated with significant complications. Thoracotomy is expected to reduce the risk of reoperation and to enhance the surgical outcomes. We retrospectively analyzed two operative approaches (thoracotomy vs. sternotomy) in cardiac reoperation. Materials and Methods: From September 2007 to December 2010, 35 patients who required reoperation of the mitral valvular disease following previous median sternotomy were included. Average age of patients was $45.8{\pm}15.4$ years (range, 14 to 76 years) and male-to-female was 23:12. Interval period between primary operation and reoperation was $135.8{\pm}105.6$ months (range, 3.3 to 384.9 months). Results: Comparative analysis was done dividing the patient group into two groups that are thoracotomy group (22 patients) and sternotomy group (13 patients). Thoracotomy group was significantly lower in operative time ($415.2{\pm}90.3$ vs. $497.5{\pm}148.0$, p<0.05), bleeding control time ($108.0{\pm}29.5$ vs. $146.4{\pm}66.8$, p<0.05) and chest tube drainage ($287.5{\pm}211.5mL$ vs. $557.3{\pm}365.5mL$, p<0.05) compared to sternotomy group. Conclusion: The thoracotomy approach is superior to sternotomy in some variables, and it is considered as a valid alternative to repeat median sternotomy in patients who underwent a previous median sternotomy.

• Journal of Magnetics
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• v.21 no.2
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• pp.215-221
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• 2016

We conducted a phased electromagnetic forming process analysis (EFPA) over time through a coupling of electromagnetic analysis and structural analysis. The analysis is conducted through a direct linkage between electromagnetic analysis and structural analysis. The analysis process is repeated until the electric current is completely discharged by a formed coil. We calculate the forming force that affects the workpiece using MAXWELL, a commercial electromagnetic finite element analysis program. Then, we simulate plastic behavior by using the calculated forming force data as the forming force input to ANSYS, a commercial structure finite element analysis program. We calculate the forming force data by using the model shape in MAXWELL, a commercial electromagnetic finite element analysis program. We repeat the process until the current is fully discharged by the formed coil. Our results can be used to reduce the error in data transformation with a reduced number of data transformations, because the proposed approach directly links the electromagnetic analysis and the structural analysis after removing the step of the numerical analysis of a graph describing the forming force, unlike the existing electromagnetic forming process. Second, it is possible to simulate a more realistic forming force by keeping a certain distance between nodes using the re-mesh function during the repeated analysis until the current is completely discharged by the formed coil, based on the MAXWELL results. We compare and review the results of the EFPA using the peak value of the forming force that acts on the workpiece (which is the existing analysis method), and the proposed phased EFPA over time approach.

• Korean Journal of Health Education and Promotion
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• v.19 no.3
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• pp.135-152
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• 2002

Objectives: Cancer is the most frequent cause of death in Korea. Cancer screenings can save lives through early detection and their effect can be enhanced by regular repeat adherence rather than one-time screening. The aim of this study was to investigate major cancer screening rates and the reasons for not having screening for providing the basic data required. Materials and Methods: The study sample were recruited from the parents of students in 3 different middle and high schools in Pusan. 428 participants(l93 of males, 214 of females) completed a structured self-administered questionnaire from Dec. 21 to 31, 2001 and the response rate was 73.8%. Data were analyzed using descriptive statistics with SPSS Win 10.0. Results: The cancer screening rates of the subjects(male and female respectively) who have had one or more in their life-time were about 36.3% and 34.6% in gastroendoscopy for stomach cancer, about 11.1 % and 8.5% in stool hemocult test and colonoscopy for colon cancer, 13.5% and 9.3% in prostate-antigen test and rectal digit exam for prostate cancer, 36.4% in mammograpy for breast cancer, and 59.3% in Pap smear test for cervical cancer. And the higher proportions of having regular screening were 36.0% in Pap smear test for cervical cancer and 11.7% in mammograpy for breast cancer. The reasons related to not having screening tests were found that ‘seem to be healthy’ was 44.8%∼58.9% and the most common reason and the following was ‘not having opportunity for check-up’. The most common reason related to not having regular screening tests were ‘for the finding of previous check-up was normal’.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1443-1448
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• 2007

In this paper, we implement a distributed computing environment-based travel information service that can use web(internet) and speech interface at the same time and can apply location information, using voice and web browser-based VoiceXML and GPS, to escape the limitations of traditional web(internet)-based travel information services. Because of IVR(Interactive Voice Response) of traditional call center has operated to a pre-installation scenario, it takes much a service time and has the inconveniences that must repeat speech recording according to the revised scenarios in case change response contents. However, suggested VoiceXML and GPS-based travel information service system has advantages that reorganization of system setups is easy, because it consists of the method to update server after make individual conversation scenarios by file format(document), and can provide usefully various travel information in environmental restriction conditions such as the back regions environment, according as our prototype find user's present location using GPS information and then provide various travel information service by this information.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.191-197
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• 2006

Recently, the earth scale disaster is occurring frequently. Under the effects of global warming, the weather has become unseasonable worldwide. Hence, the earth is experiencing unstable condition with many disasters such as storms and flood damages as well as earthquake. Therefore, it is necessary to consider what we can do to prevent disasters. A disaster like earthquake will inevitably occur in view of the probabilities. The active period of earthquakes and the inactive periods repeat alternatively. Consequently, recent warnings indicate that there is a potential risk of massive earthquakes. Consideration of the effects of tsunami to the moored ship is very important. Operational problems such as moored ship motions sometimes become remarkable with large amplitude and long periods in harbor. Moored ship motions may cause the breakage of mooring systems such as mooring lines, fenders or quay. Large and long period moored ship motions are caused by resonant effects. In this paper, the moored ship motions within a harbor by the large-scale tsunami and the effects on the motions and mooring loads with resonant effects are investigated by numerical simulations.

• Journal of Korean Neurosurgical Society
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• v.56 no.3
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• pp.224-229
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• 2014

Objective : To report long-term clinical and radiological outcomes of minimally invasive posterior cervical foraminotomy (MI-PCF) performed in patients with unilateral single-level cervical radiculopathy. Methods : Of forty-six patients who underwent MI-PCF for unilateral single-level radiculopathy between 2005 and 2013, 33 patients were included in the study, with a mean follow-up of 32.7 months. Patients were regularly followed for clinical and radiological assessment. Clinical outcome was measured by visual analogue scale (VAS) for the neck/shoulder and arm, and the neck disability index (NDI). Radiological outcome was measured by focal/global angulation and disc height index (DHI). Outcomes after MI-PCF were evaluated as changes of clinical and radiological parameters from the baseline. Mixed effect model with random patients' effect was used to test for differences in the clinical and radiological parameters repeat measures. Results : There were no complications and all patients had an uneventful recovery during the early postoperative period. VAS scores for neck/shoulder and arm improved significantly in the early postoperative period (3 months) and were maintained with time (p<0.001). NDI improved significantly post-operatively and tended to decrease gradually during the follow-up period (p<0.001). There were no statistically significant changes in focal and global angulation at follow-up. Percent DHIs of the upper adjacent or operated disc were maintained without significant changes with time. During the follow-up, same site recurrence was not noted and adjacent segment disease requiring additional surgery occurred in two patients (6%) on the contra-lateral side. Conclusion : MI-PCF provides long-term pain relief and functional restoration, accompanied by good long-term radiological outcome.