• Restorative Dentistry and Endodontics
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• v.32 no.2
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• pp.130-137
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• 2007

This in vitro study examined the effect of surface defects on cutting blades on the extent of the cyclic fatigue fracture of HEROShaper Ni-Ti rotary files using fractographic analysis of the fractured surfaces. A total of 45 HEROShaper (MicroMega) Ni-Ti rotary flies with a #30/.04 taper were divided into three groups of 15 each. Group 1 contained new HEROShapers without any surface defects. Group 2 contained HEROShapers with manufacturing defects such as metal rollover and machining marks. Croup 3 contained HEROShapers that had been clinically used for the canal preparation of 4-6 molars A fatigue-testing device was designed to allow cyclic tension and compressive stress on the tip of the instrument whilst maintaining similar conditions to those experienced in a clinic. The level of fatigue fracture time was measured using a computer connected the system. Statistical analysis was performed using a Tukey's test. Scanning electron microscopy (SEM) was used for fractographic analysis of the fractured surfaces. The fatigue fracture time between groups 1 and 2, and between groups 1 and 3 was significantly different (p<0.05) but there was no significant difference between groups 2 and 3 (p>0.05). A low magnification SEM views show brittle fracture as the main initial failure mode At higher magnification, the brittle fracture region showed clusters of fatigue striations and a large number of secondary cracks. These fractures typically led to a central region of catastrophic ductile failure. Qualitatively, the ductile fracture region was characterized by the formation of microvoids and dimpling. The fractured surfaces of the HEROShapers in groups 2 and 3 were always associated with pre-existing surface defects. Typically, the fractured surface in the brittle fracture region showed evidence of cleavage (transgranular) facets across the grains, as well as intergranular facets along the grain boundaries. These results show that surface defects on cutting blades of Ni-Ti rotary files might be the preferred sites for the origin of fatigue fracture under experimental conditions. Furthermore this work demonstrates the utility of fractography in evaluating the failure of Ni-Ti rotary flies.

• Journal of Nutrition and Health
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• v.50 no.2
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• pp.142-157
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• 2017

Purpose: The purpose of this study was to develop a nutrition quotient for adolescents (NQ-A) to assess overall dietary quality and food behavior of Korean adolescents. Methods: Development of the NQ-A was undertaken in three steps: item generation, item reduction, and validation. Candidate items of the NQ-A checklist were selected based on literature reviews, results of the fifth Korea National Health and Nutrition Examination Survey data, dietary guidelines for Korean adolescents, expert in-depth interviews, and national nutrition policies and recommendations. A total of 213 middle and high school students participated in a one-day dietary record survey and responded to 41 items in the food behavior checklist. Pearson's correlation coefficients between the responses to the checklist items along with nutritional status of the adolescents were calculated. Item reduction was performed, and 24 items were selected for the nation-wide survey. A total of 1,547 adolescents from 17 cities completed the checklist questionnaire. Exploratory factor and confirmatory factor analyses were performed to develop a final NQ-A model. Results: Nineteen items were finalized as the checklist items for the NQ-A. Checklist items were composed of five factors (balance, diversity, moderation, environment, and practice). The five-factor structure accounted for 47.2% of the total variance. Standardized path coefficients were used as weights of the items. The NQ-A and five-factor scores were calculated based on the obtained weights of the questionnaire items. Conclusion: Nutrition Quotient for adolescents (NQ-A) would be a useful instrument for evaluating dietary quality and food behavior of Korean adolescents. Further research on NQ-A is needed to reflect changes in adolescent's food behavior and environment.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.537-544
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• 2017

Stable carbon isotope ratio of carbon dioxide (${\delta}^{13}C_{CO2}$) is used as an important indicator in the researches for global climate change and carbon capture and sequestration technology. The ${\delta}^{13}C$ value has been usually analyzed with Isotope Ratio Mass Spectrometer (IRMS). Recently, the use of Laser Absorption Spectrometry (LAS) is increasing because of the cost efficiency and field applicability. The purpose of this study was to suggest practical procedures to prepare laboratory reference gases for ${\delta}^{13}C_{CO2}$ analysis using LAS. $CO_2$ gas was adjusted to have the concentrations within the analytical range. Then, the concentration of $CO_2$ was assessed in a lab approved by the Korea Laboratory Accreditation Scheme and the ${\delta}^{13}C_{CO2}$ value was measured by IRMS. When the instrument ran over 12 hours, the ${\delta}^{13}C$ values were drifted up to ${\pm}10$‰ if the concentration of $CO_2$ was shifted up to 1.0% of relative standard deviation. Therefore, periodical investigation of analytical suitability and correction should be conducted. Because ${\delta}^{13}C_{CO2}$ showed the dependency on $CO_2$ concentration, we suggested the equation for calibrating the concentration effect. After calibration, ${\delta}^{13}C_{CO2}$ was well matched with the result of IRMS within ${\pm}0.52$‰.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.487-495
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• 2017

A granite rock body, called 'Bukbawi', located on a mountaineering trail at Mt. Palgong Provincial Park is popular among the public because it resembles a percussion instrument. If someone hits the specific surface area of this rock body, people can hear drum-like sound. Such phenomenon may be geologically associated with exfoliation process of the granite body or miarolitic cavity developed after gasses escaped during formation of granite. To understand better the inner structure causing drum-like sound, we carried out a non-destructive ground-penetrating radar survey. In this study, as our primary target is very close to the surface, we utilized 1 GHz antennas to produce high-resolution near-surface images. In order to construct 3-D internal images, the measurements were conducted along a pre-defined grid. The processed radargrams revealed that the locations associated with 'drum' sound coincide with strong reflections. In addition, both reflection patterns of fracture and cavity were observed. To further quantify the observed reflections, we simulated GPR scans from a synthetic fracture in a granite body, filled with different materials. The simulated results suggest that both exfoliation process and miarolitic cavity may have contributed to the 'drum' phenomena. Furthermore, the radargrams showed a well-developed cavity signature where two major reflection planes were crossed. Thus, our study is an example of non-destructive geophysical studies that can promote Earth Science in the broader community by examining geological structures attracting the public.

• Journal of Hospice and Palliative Care
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• v.5 no.1
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• pp.31-42
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• 2002

Purpose : The purpose of this study was to evaluate the present status of hospice palliative care programs in Korea as a basic database for standardization of hospice palliative care. Method : The data was collected from July to October, 2001. The instrument used for this study was the questionnaires which was consisted of the general characteristics of organization, recipient of service, manpower, contents of service, financial conditions and facilities. Sixty-four hospice palliative care programs answered the questionnaires, confirmed by telephone. Results : They were 40 hospital-based hospice palliative care programs and 24 nonmedical hospice palliative care programs. 11 Hospital-based hospice palliative programs have isolated unit or hospital affiliated free standing hospice. 6 Non-hospital hospice palliative programs have a free standing hospice. Major subjects of hospice palliative program were terminal cancer patients but patients with non-terminal illness were also included. Only 24 of 64 hospice palliative programs had all of the essential professionals : physicians, nurses, social workers, and clergies. Home hospice palliative care programs have a referral system in hospital based (89.7%) and nonmedical programs (73.7%). 24hr hospice are were provided in 26 hospital-based (65.0%) and 9nonmedical programs (37.5%). There were rooms for family in half of hospital-based programs. 73.9% of hospice palliative care programs have financial problems. 62.0% of Hospice palliative care programs need financial support from government. Conclusion : 64 Hospice palliative care programs provided hospice palliative services but had many problems in manpower, quality of care and facility. For improving the quality of terminal patients' life and promoting the cost effectiveness of health care resources, it is necessary to consider the standardization and institutionalization of hospice palliative care.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.388-394
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• 2010

Metabolomics aims at the comprehensive, qualitative and quantitative analysis of wide arrays of endogenous metabolites in biological samples. It has shown particular promise in the area of toxicology and drug development, functional genomics, system biology and clinical diagnosis. In this study, analytical technique of MS instrument with high resolution mass measurement, such as time-of-flight (TOF) was validated for the purpose of investigation of amino acids, sugars and fatty acids. Rat urine and serum samples were extracted by selected each solvent (50% acetonitrile, 100% acetonitrile, acetone, methanol, water, ether) extraction method. We determined the optimized liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) system and selected appropriated columns, mobile phases, fragment energy and collision energy, which could search 17 metabolites. The spectral data collected from LC/TOFMS were tested by ANOVA. Obtained with the use of LC/TOFMS technique, our results indicated that (1) MS and MS/MS parameters were optimized and most abundant product ion of each metabolite were selected to be monitorized; (2) with design of experiment analysis, methanol yielded the optimal extraction efficiency. Therefore, the results of this study are expected to be useful in the endogenous metabolite fields according to validated SOP for endogenous amino acids, sugars and fatty acids.

• Journal of the Korean Society for Library and Information Science
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• v.12
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• pp.269-327
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• 1985

This study was undertaken to meet more fully the demands for improved training of library personnel, occasioned by the rapidly changing roles and functions of libraries as they try to adapt to the vast social, economic and technological changes currently in progress in the Korean society. The specific purpose of this research is to develop a standard curriculum at the batchelor's level that will properly equip the professional personnel in Korean libraries for the changes confronting them. This study started with the premise that to establish a sound base for curriculum development, it was necessary first to determine what concepts, knowledge, and techniques are required for professional library personnel to perform it at an optimal level of efficiency. Explicitly, it was felt that for the development of useful curricula and courses at the batchelor's level, a prime source of knowledge should be functional behaviours that are necessary in the job situation. To determine specifically what these terminal performance behaviours should be so that learning experience provided could be rooted in reality, the decision was reached to use a systems approach to curriculum development, which is an attempt to break the mold of traditional concepts and to approach interaction from an open, innovative, and product-oriented perspective. This study was designed to: (1) identify what knowledge and techniques are required for professional library personnel to perform the job activities in which they are actually engaged, (2) to evaluate the educational needs of the knowledge and techniques that the professional librarian respondents indicate, and (3) to categorise the knowledge and techniques into teaching subjects to present the teaching subjects by their educational importance. The main data-gathering instrument for the study, a questionnaire containing 254 items, was sent to a randomly selected sample of library school graduates working in libraries and related institutions in Korea. Eighty-three librarians completed and returned the questionnaire. After analysing the returned questionnaire, the following conclusions have been reached: (A) To develop a rational curriculum rooted in the real situation of the Korean libraries, compulsory subjects should be properly chosen from those which were ranked highest in importance by the respondents. Characters and educational policies of, and other teaching subjects offered by, the individual educational institution to which a given library school belongs should also be taken into account in determining compulsory subjects. (B) It is traditionally assumed that education in librarianship should be more concerned with theoretical foundations on which any solution can be developed than with professional needs with particulars and techniques as they are used in existing library environments. However, the respondents gave the former a surprisingly lower rating. The traditional assumption must be reviewed. (C) It is universally accepted in developing library school curricula that compulsory subjects are concerned with the area of knowledge students generally need to learn and optional subjects are concerned with the area to be needed to only those who need it. Now that there is no such clear demarcation line provided in librarianship, it may be a realistic approach to designate subjects in the area rated high by the respondents as compulsory and to designate those in the area rated low as optional. (D) Optional subjects that were ranked considerably higher in importance by the respondents should be given more credits than others, and those ranked lower might be given less credits or offered infrequently or combined. (E) A standard list of compulsory and optional subjects with weekly teaching hours for a Korean library school is presented in the fourth chapter of this report.

• Journal of Music and Human Behavior
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• v.3 no.1
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• pp.1-11
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• 2006

It has been passed more than 50 years of the history of music therapy on school aged children since there had been enforced the 'Education for All Handicapped Children Ace' in United states 1975, which had made an important role of music therapist augmented. In the case of South Korea, through reforming the law on March 2005 that therapist educator has to be allocated on the special class in general school, at least, patrol teacher is charged on that, which made possible to start music therapy as initial stage was realized in realistic way on the spot of school. This research has primary concerns as following. The one thing is intended that figuring the opinions of special educators and music therapists involved with the music therapy in elementary school. And the other thing is intended that making a investigation of actual condition on the spot of existing school, moreover, pinpointing at issue and suggesting the change for the better than now. In order to undertake theses intentions, I examined preceding researches and existing data, distributed the questionnaire involved the music therapy of elementary school to the people who are composed of special educators-65 persons and music therapists-30 persons from 18th October to second of November, and analyzed collected by descriptive statistics. According to the analyzed results, it says that special educator and music therapist know well about the necessity of music therapy in elementary school and its effectiveness is manifested in positive way. Moreover, in order to systemize and promote a program of music therapy, what is most urgent thing is the completion of instrument and music therapy room and there are needed strong supports at the level of nation and institution. It has become pervasive on the demand of therapy education by parents in all of the places involved with disabled children such as special school, special class, local welfare community, and early education. This research shows that how therapy and education was connected as music therapy on the spot of the elementary school, and the necessity of the education of music therapy.

• Journal of Korean Home Economics Education Association
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• v.16 no.1
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• pp.79-91
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• 2004

The purpose of this study was to examine how much secondary school home economics teachers paid attention to performance assessment, to what extent and in which way they carried it out and how much support was given to that. It's basically meant to help provide more systematic support for performance assessment. The instrument used in this study was an Interest-Based Reform Adoption Model developed by Hall. Hord and et. al. at Texas University Research & Development Center for Teacher Education. and the subjects in this study were home economics teachers from 95 secondary schools in Gyeonggi province. After a survey was conducted by mail. the responses from 157 teachers were chosen for analysis. For data handling. SPSS/WIN program was utilized, and statistical data on mean. standard deviation and percentage were obtained. In addition. t-test and ANOVA were employed. The major findings of this study were as follows: First. as for their type of interest in performance assessment. influential type(35.0%) was most common. followed by confident type (29.3%). indifferent type(20.4%) and task type(15.3%). Second, regarding their implementation. every teacher carried out performance assessment. The largest group of the teachers fulfilled it as part of routine daily schedule(60 teachers. 38.2%). which could be called the level 4. The second largest group tried to integrate performance assessment to education programs(53 teachers. 33.8%). which could be called the level 5. The third largest group implemented it without making careful preparations for that(26 teachers. 16.6%). which could be called the level 3. and the fourth largest group tried to reinvent it(11 teachers. 7.0%), which could be called the level 6. The fifth largest group was in the middle of researching it(5 teachers, 3.2%). which could be called the level 1. And the sixth largest group was in the course of making preparations for that(2 teachers. 1.3%) . which could be named the level 2. Third. concerning how much they found themselves to be supported about performance assessment. they eave three or less marks to that. which showed that they weren't supported sufficiently There was little gap among them in their concern for performance assessment and its implementation levels. and this fact suggested that there wasn't satisfactory backup for their performance assessment.

• Journal of Korean Home Economics Education Association
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• v.19 no.3
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• pp.61-76
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• 2007

The purpose of the study is to identify and understand problems existing in the middle school home economics practice rooms in Jeju Special Self-Governing Province. The findings are based on the examination and the analysis of the indoor environment and the condition of the facilities and equipment. Study method employs on-site research and a survey. The on-site research was conducted about temperature, humidity, intensity of illumination, and status of teaching instrument in 10 out of 41 middle schools in Jeju Special Self-Governing Province from August 16 to September 30, 2006. Meanwhile, the survey was implemented by mail for 95 teachers in charge of manual training and home economics education in 41 middle schools in Jeju from November 1 to 23, 2005. 64 questionnaires out of total 95 were collected, including those collected during the period of on-site research. Finally, 61 questionnaires which were effective among the answered ones were used for analysis. Collected materials were analyzed with the SPSS Win.12.0 program for frequency, percentile analysis. In conclusion, the study determines that the condition of the home economics practice rooms of the middle school in JSSGP in terms of temperature, humidity, lighting and ventilation is very inadequate. The structure of the practice room represents an inefficient work flow pattern. Further, the facilities and equipment are in a very poor condition because the facilities are old and the retention rate of teaching tools is low. Therefore, to address these problems, the study suggests that improvements on the facilities and equipment should be made and teaching tools should be replenished in accordance with the industry standard.