• The Journal of Korean Academy of Prosthodontics
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• v.43 no.3
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• pp.306-313
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• 2005

Statement of problem. There have been many studies about marginal discrepancy of single restorations made by various systems and materials. But most of statistical inferences are not definite because of sample size, measurement number, measuring , instruments, etc. And there have been few studies about the marginal fit of Computer-aided Cercon crowns. Purpose. The purpose of this study was to compare the marginal fit of the anterior single restorations made using computer-aided milled Cercon crowns with metal-ceramic restorations and to obtain more accurate information by using a large enough sample size and by making sufficient measurements per specimen. Material and methods. The in vitro marginal discrepancies of computer-aided milled Cercon crowns and control groups (metal ceramic crowns) were evaluated and compared. The crowns were made from one extracted maxillary central incisor prepared by milling machine. 30 crowns per each system were fabricated. Measurements of a crown were recorded at 50 points that were randomly selected for marginal gap evaluation. Parametric statistical analysis was performed for the results. Results. The means and standard deviations of the marginal fit were 85$\pm$22$\mu$m for the control group and 91$\pm$15$\mu$m for the Cercon crowns. The t-test of the marginal discrepancies between Cercon crowns and metal-ceramic crowns were performed. Significant differences were not found between groups (P=0.230>.05). Based on the criterion of 120$\mu$m as the limit of clinical acceptability, the mean marginal fits of Cercon crowns and metal-ceramic crowns were acceptable. Conclusion. Within the limitations of this in vitro study, the following conclusions were drawn: 1. Mean gap dimensions and standard deviations at the marginal opening for maxillary incisal crowns were 85$\pm$22$\mu$m for the control (metal-ceramic crowns), 91$\pm$15$\mu$m for Cercon crowns. 2. The Cercon crowns showed slightly larger marginal gap discrepancy than the control but marginal gap between Computer-aided milled Cercon crowns and metal ceramic crowns did not showed significant difference (P>.05). 3. The Cercon crowns and metal ceramic crowns showed clinically acceptable marginal discrepancy.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.278-283
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• 2017

Purpose: The aim of this study was to evaluate the interdental distances of anterior, premolar, and molar teeth at the cementoenamel junction (CEJ) and 2 mm below the CEJ in healthy natural dentition with cone-beam computerized tomography (cone-beam CT) in order to provide valuable data for ideal implant positioning relative to mesiodistal bone dimensions. Materials and Methods: Two hundred patients who visited Dental Hospital, Wonkwang University, who had natural dentition with healthy interdental papillae, and who underwent cone-beam CT were selected. The cone-beam CT images were converted to digital imaging and communication in medicine (DICOM) files and reconstructed in three-dimensional images. To standardize the cone-beam CT images, head reorientation was performed. All of the measurements were determined on the reconstructed panoramic images by three professionally trained dentists. Results: At the CEJ, the mean maxillary interdental distances were 1.84 mm (anterior teeth), 2.07 mm (premolar), and 2.08 mm (molar), and the mean mandibular interproximal distances were 1.55 mm (anterior teeth), 2.20 mm (premolar), and 2.36 mm (molar). At 2mm below the CEJ, the mean maxillary interdental distances were 2.19 mm (anterior teeth), 2.51 mm (premolar), and 2.60 mm (molar), and the mean mandibular interproximal distances were 1.86 mm (anterior teeth), 2.53 mm (premolar), and 3.01 mm (molar). Conclusion: The interdental distances in the natural dentition were larger at the posterior teeth than at the anterior teeth and also at 2 mm below the CEJ level compared with at the CEJ level. The distances between mandibular incisors were the narrowest and the distances between mandibular molars were the widest in the entire dentition.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.4
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• pp.333-346
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• 2002

The continuous indentation techniques are one of the most effective methods to nondestructively estimate mechanical properties. There are many applications in various dimensions of materials from macro-scale, through micro-scale, even to nano-scale range. The macro-range technology of kgf-load level is now focused on the evaluation of tensile properties and residual stress of bulk materials, for example, used in conventional load-bearing structures and in-use pipelines. The technology and the apparatus were successfully developed by a domestic research group. The micro-range technology of gf-load level can be applied to investigate some property-gradient materials such as weldment. Because it has better spatial resolution than the macro-range technology. The nano-range technology (called nanoindentation technique) of mgf-load level is basically used to evaluate hardness and modulus of micro- and nano-materials. Moreover, many researches are going on to measure tensile properties and residual stress. The nanoindentation technology is easy to be applied to the various fields, such as semiconductor devices, multiphase materials, and biomaterials, though other methods are too difficult to be applied due to dimensional or environmental limitations. On the basis of these accomplishments, the international and the domestic standards are being established.

• Journal of the Korea Concrete Institute
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• v.26 no.4
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• pp.491-497
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• 2014

The corrosion of steel reinforcement in reinforced concrete bridge decks significantly affects the degradation of the capacity. Due to the advantageous characteristics such as high tensile strength and non-corrosive property, fiber reinforced polymer (FRP) has been gathering much interest from designers and engineers for possible usage as a alternative reinforcement for a steel reinforcing bar. However, its application has not been widespread, because there data for short- and long-term performance data of FRP reinforced concrete members are insufficient. In this paper, seven full-scale decks with dimensions of $4000{\times}3000{\times}240mm$ were prepared and tested to failure in the laboratory. The test parameter was the bottom reinforcement ratio in transverse direction. The decks were subjected to various levels of concentrated cyclic load with a contact area of $577{\times}231mm$ to simulate the vehicle loading of DB-24 truck wheel loads acting on the center span of the deck. It was observed that the glass FRP (GFRP) reinforced deck on a restraint girder is strongly effected to the level of the applied load rather than the bottom reinforcement ratio. The study results showed that the maximum load less than 58% of the maximum static load can be applied to the deck to resist a fatigue load of 2 million cycles. The fatigue life of the GFRP decks from this study showed the lower and higher fatigue performance than that of ordinary steel and CFRP rebar reinforced concrete deck. respectively.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.897-908
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• 2019

The objective of this study is to evaluate the field support performance of highperformance lattice girder (BK-Lattice Girder) by using numerical analysis. Three types (50, 70, 95-type) of existing and high performance lattice girders were applied to the cross section of highway 2, 3, and 4 lane tunnels to compare the supporting performance. The numerical analysis was the finite element method and the lattice girder was modeled in three dimensions with an elasto-plastic frame. The ground was modeled as a spring receiving only compression. The load was applied as a concentrated load on the central ceiling of the tunnel section. The yield strengths of the lattice girders were determined from the numerical results to compare the supporting performance of lattice girder. In case of 50-type, the yield strengths of high-performance lattice girders were increased by 6.7~10.0% compared with those of the existing lattice girders. In the case of 70-type, the high-performance lattice girders increased yield strengths by 12.1~14.9% than the existing lattice girder. In the case of 95-type, the high-performance lattice girders increased yield strengths by 13.3~20.0% than the existing lattice girder. As a result of numerical analysis, it was considered that the high-performance lattice girder supported better than the existing lattice girder when only the lattice girders were constructed.

• The Journal of the Korea Contents Association
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• v.20 no.7
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• pp.379-391
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• 2020

The growth paradigm that has led Korea for the last few decades is now reaching its critical point. Rather than focusing on the outcomes created by severe competitions of individual companies, a growth based on win-win system and solidarity focusing on public interests is more called for. In this background, I would like to examine the concept of corporate publicness and what factors consist of it. The study aims to verify a causal relationship that corporate publicness affects the corporation's social responsibility and consumers' favorability and credulity toward the company, and looks for the possibility that corporate publicness is recognized as a corporation's substantive competitiveness and an important management activity for its sustainability. The results of the study shows that corporate publicness is composed of 5 dimensions: sincerity, activeness, pursuit of public interest, harmony, and community spirit. Then the study statistically verifies that corporate publicness significantly has a positive impact on the overall evaluation results of a corporation's social responsibility. Lastly, the study confirms that corporate publicness and socially responsible activity of a company have a positive influence overall on the attitude toward the corporate brand. Based on these results, an implication is drawn that strengthening corporate publicness and its practice in action should be emphasized for a corporation to keep making outstanding performances in a sustainable way.

• Journal of Korean Academy of Nursing
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• v.6 no.1
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• pp.12-22
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• 1976

Amongst varieties of clinical nursing role, the administration of medication is often highlighted as of prime importance. In order to attain data for the improvement of teaching strategies of medication, diagnostic evaluation of the knowledge level is a necessity. This study was performed from August through December 1975. 449 registered nurses, randomly sampled from general hospitals:16 of Seoul and 7 of Taegu and Pusan, were tested through 54 test questionaries based on 4 practical dimensions of administration of medication. Results are as follows ; 1. Status of respondents: Length of clinical experiences; the average length revealed to be 2 years and 7 months, 72% revealed to have had less than 3 years of experience; 38.6%-less than 1 year, 19 .2%-over 1 year and less than 2 years, and 14, 2%-over 2 years and less than 3 years. Type of Nursing education received ; 9.4% revealed to have graduated technical high school of nursing, 67.5o/o the 3 year diploma school and 21, 7% the baccalaureate degree program. The knowledge Level; Degree of self-satisfaction on knowledge level revealed that;27, 4% responded to "more or less satisfied", 48.8% "more or less un-satisfied" and 19.8% to "not satisfied". The average level of basic knowledge revealed to be moderate by 66.95 points. The level of knowledge of 4 questionnaire categories revealed that; drug action category by average of 66.5 points, methodology category by 65.4 Points, safety measure category by 71.4 points and terminology and concepts category by 64.6 points, Questionnaire items which revealed high points are of;6 of drug action category, 4 of methodology, 4 of safety measure, and 3 of terminology. The items of low points are: 8 of drug action, 3 of methodology, 3 of safety measure and 5 of terminolology categories. 3. The type of nursing education revealed to have no significant influence on the level of knowledge on the administration of medication. 4. The length of clinical experience revealed to have no significant influence on the level of knowledge. 5. 75. l% responded that the actual practice of medication modes are "similar" to that included in the fundamentals of nursing course. 6. In-service education on medication; 54.0% revealed to have some incidental in-service education on medication while 34.0% receive programmed in- service education. 61.8% revealed to have expressed the need of systemic In-service education as one of the means for improvement of medication. 32.7% revealed to obtain information concerning medicine by reading commercial publications on drug package, while only 20.9% by reading specific information channel.

• The Journal of Korean Academic Society of Nursing Education
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• v.9 no.2
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• pp.298-309
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• 2003

The educational preparation of nurses has been the focus of considerable debate globally. It is needed the change of the basic nursing education for professional nurse to prepare the trends of the health care needs of clients for coming new generation. And also it is believed that educational preparation for being nurses is to be responsible to clients' needs. The purpose of the study was to develop a baccalaureate program in nursing. This study were implemented through three stages from April 2001, to April 2002.: preparation stage which were consisted of reviewing of the literatures, interviewing the fellow nurses in a variety workplace, and consulting professors who were concerned with the nursing education to identify the present educational problems, and analyzing the contents of seven major courses in nursing education, evaluation stage about a new developed curriculum with the directors of the five nursing schools, and confirmation stage of new developed education programme. The developed education programme was designed as a four year program with 126 credit hours including 39 credit hours of liberal arts, 34 credit hours of supplementary courses, and 53 credit hours of nursing major based on the four basic nursing dimensions of human, health, environment and nursing. Nursing majors were consisted of Nursing Ⅰ(oxygenation), Nursing Ⅱ(nutrition elimination), Nursing Ⅲ(activity rest), Nursing Ⅳ(neurologic- endocrine protection), Nursing Ⅴ(fluids electrolytes/sex reproductive), Nursing Ⅵ(psycho-social), Community Health Nursing, Fundamental Nursing, School Health, and Emergency care. This new nursing programme was focused on the nursing education for prevention and rehabilitation nursing care as well as the acute and chronic nursing care at hospital, on the integrated nursing programme to become effective, and the nursing process to encourage the critical thinking. The new education programme focused on the professional nurses who are responsible the nursing ethics, communication skills, and professional beliefs to suit the future trends in health. And also it will be needed for faculties to manage the integrated curriculum, to analyze the contents of each subject, and to communicate with each other before a new education programme apply to their education programme in future. This research was supported by the Han Kok Medical Science Foundation

• Imaging Science in Dentistry
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• v.32 no.2
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• pp.75-79
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• 2002

Purpose : To evaluate the effect of exposure time and image resolution on fractal dimension calculations for determining the optimal range of these two variances. Materials and Methods : Thirty-one radiographs of the mandibular angle area of sixteen human dry mandibles were taken at different exposure times (0.01, 0.08, 0.16, 0.25, 0.40, 0.64, and 0.80 s). Each radiograph was digitized at 1200 dpi, 8 bit, 256 gray level using a film scanner. We selected an Region of Interest (ROI) that corresponded to the same region as in each radiograph, but the resolution of ROI was degraded to 1000, 800, 600, 500, 400, 300, 200, and 100 dpi. The fractal dimension was calculated by using the tile-counting method for each image, and the calculated values were then compared statistically. Results: As the exposure time and the image resolution increased, the mean value of the fractal dimension decreased, except the case where exposure time was set at 0.01 seconds (α = 0.05). The exposure time and image resolution affected the fractal dimension by interaction (p<0.001). When the exposure time was set to either 0.64 seconds or 0.80 seconds, the resulting fractal dimensions were lower, irrespective of image resolution, than at shorter exposure times (α = 0.05). The optimal range for exposure time and resolution was determined to be 0.08- 0.40 seconds and from 400-1000 dpi, respectively. Conclusion : Adequate exposure time and image resolution is essential for acquiring the fractal dimension using tile-counting method for evaluation of the mandible.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.2
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• pp.328-339
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• 2010

This study was conducted to develop a service quality measurement scale suitable for the fast food restaurant segment. After reviewing the relevant literature, it was decided that the current service quality measurement scales (SERVQUAL, SERVPERF, DINESERV) are not appropriate for the fast food restaurant segment. Based on Cronin & Taylor's (1994) argument, perceived service quality is a form of attitude that represents a long-term overall evaluation of the company. Therefore, this study selected SERVPERF items for the initial pool of service quality items. Through a systematic scale development process, the SERVPERF instrument was then refined and a new concise scale was produced. Specifically, a focus group discussion with a group of patrons who are very familiar with fast food restaurants was conducted and the new service quality measure was refined so that it would be more realistic and closely describe service operation in the fast food industry. Moreover, the data collected from 112 college students who visit fast food restaurants frequently were used to statistically evaluate each of the items again via EFA (Exploratory Factor Analysis) and three sub-dimensions were derived: (1) responsiveness, (2) tangibles, and (3) reliability. Additionally, the data collected from 179 fast food restaurant consumers was used to conduct CFA (Confirmatory Factor Analysis). During this process, the convergent validity, discriminant validity, and internal consistency were double-checked. Overall, the newly developed scale achieved validity and reliability on a theoretical and statistical basis. Possible interpretations and managerial implications are also suggested.