• Communications of Mathematical Education
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• v.22 no.1
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• pp.41-52
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• 2008

In this paper, some factors such as the perspective of children, instructional materials(especially activities in textbooks for elementary school mathematics), and teacher's questioning styles are discussed as ones influenced on students' immersion in leaner-centered instruction. This discussion is based on the author's two implementations of the kind of two instructions. About the first theme, constructivists assert that even children who are in elementary school can have reflective abstracting ability. Teachers' asking questions with the belief differ from ones with traditional perspective of children, which is relevant the third factor. They value and respect learners' thinking outcomes, even though they are not sometimes wrong and have errors. Also, they have them opportunities to think different from others and to ask how they get their answers. To do these, they frequently ask open-ended questions, not closed. All of them is possible through the activities provided in textbooks. Some characteristics which can prompt such teacher's questions using activities in elementary mathematics textbooks are discussed.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.3
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• pp.221-227
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• 2000

Provisional fixed partial dentures(FPDs) are an important part of many prosthodontic treatment procedures. These provisional fixed prostheses must fulfill biologic, mechanical, and esthetic requirements to be considered successful. Consideration of all these factors and requirements are important because provisional resin restorations may be worn over a long period to assess the results of periodontal and endodontics therapies, and also during the restorative phase of implant reconstructive procedures. This in vitro study examined flexual strength of four resins commonly used for fixed provisional prostheses. The effects of polymerization conditions were also evaluated. The four resins tested were : Caulk Temporary bridge resin(L.D. Caulk Co. Dentsply International Millford), Jet(Lang Dental Mfg. Co. Chicago. ILL. U.S.A), Alike (Coe Laboratories. Inc. Chicago. ILL. U.S.A) and Tokuso Curefast (Coe Laboratories. Inc. Chicago. ILL. U.S.A) The test specimens were 65mm long, 14mm wide, and 3.5mm thickness. 10 specimens of four resins were cured for 15 minutes at atmospheric pressure and 10 specimens of four resins were cured at an additional pressure of approximately 20 psi. A total of 80 specimens were prepared. The flexual strength was determined by three-point bending test. Data were analysed with the Paired samples T-test and Tukey student-range test Within the limitations imposed in this study, the following conclusions can be drawn : 1. Under the condition of bench curing, Caulk Temporary bridge resin showed the highest flexual strength. In decreasing order, the flexual strength of the other materials was as follows : Jet, Tokuso Curefast, Alike, and Caulk Temporary bridge resin demonstrated significantly higher strength than other resins. 2. Under the condition of pressure curing, Jet showed the highest flexual strength. In decreasing order, the flexual strength of the other materials was as follows : Caulk Temporary bridge resin, Tokuso Curefast, and Alike. There were all statistically significant differences among four resins 3. There was a statistically significant difference between bench- and pressure-cured specimens in all four materials.

• Journal of Educational Research in Mathematics
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• v.18 no.3
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• pp.283-308
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• 2008

A poor achievement of basic competency leads to obstacles of the same subject and other subjects from a series of accumulative losses and social life. The Grade 3 National Diagnostic Assessment of Basic Competency (NDAHC) dated from 2002, Teaching Plan Responsible to Basic Competency and compensational education materials for students of the below-basic level has marked a line in the chain of policy to realize educational welfare. The goal of NDABC is to collect information of the reason with regard to learning deficiency and individual student's information, and ultimately teach them on the basis of those informations. This study analyzed the characteristics of below-basic students in the basic mathematics with data from NDABC from 2003 to 2007. Students of the below-basic level were affected in achievement by numerical distinction, regrouping, arrangement and descriptive form of item, information-providing way, typical example, familiarity, frequency in use in daily life etc. This study provides a basic important information with regard to teaching below-basic students and suggestions with compensational education materials for them.

• The Journal of Advanced Prosthodontics
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• v.7 no.4
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• pp.317-322
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• 2015

PURPOSE. The aim was to evaluate the effect of curing mode and different dentin surface pretreatment on microtensile bond strength (${\mu}TBS$) of self-adhesive resin cements. MATERIALS AND METHODS. Thirty-six extracted human permanent molars were sectioned horizontally exposing flat dentin surface. The teeth were divided into 12 groups (3 teeth/group) according to the dentin surface pretreatment methods (control, 18% EDTA, 10% Polyacrylic acid) and curing mode (self-curing vs. light-curing) of cement. After pretreatment, composite resin blocks were cemented with the following: (a) G-CEM LinkAce; (b) RelyX U200, followed by either self-curing or light-curing. After storage, the teeth were sectioned and ${\mu}TBS$ test was performed using a microtensile testing machine. The data was statistically analyzed using one-way ANOVA, Student T-test and Scheffe's post-hoc test at P<.05 level. RESULTS. For G-CEM LinkAce cement groups, polyacrylic acid pretreatment showed the highest ${\mu}TBS$ in the self-cured group. In the light-cured group, no significant improvements were observed according to the dentin surface pretreatment. There were no significant differences between curing modes. Both dentin surface pretreatment methods helped to increase the ${\mu}TBS$ of RelyX U200 resin cement significantly and degree of pretreatment effect was similar. No significant differences were found regarding curing modes except control groups. In the comparisons of two self-adhesive resin cements, all groups within the same pretreatment and curing mode were significantly different excluding self-cured control groups. CONCLUSION. Selecting RelyX U200 used in this study and application of dentin surface pretreatment with EDTA and polyacrylic acid might be recommended to enhance the bond strength of cement to dentin.

• Korean Journal of Clinical Pharmacy
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• v.23 no.1
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• pp.57-64
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• 2013

Purpose: Drug can be hazardous for people if misused although they are useful for their indication. In urgent incidences such as overdose, proper treatment for intoxication can save patients' lives. In emergent case regarding drug overdose, pharmacists should know how to provide correct information including antidote to other healthcare providers. However, in Korea, there is neither regular class nor education material regarding detoxification. Therefore, the object of our study is to investigate the perception of pharmacists about it. Method: We surveyed hospital pharmacists by means of self-reporting questionnaire in order to investigate the pharmacists' perception of detoxification treatments from May $12^{th}$ 2012 to August $10^{th}$ 2012. The questionnaire comprised of demographic information, interest in detoxification treatment (inquiry from patients and education about antidote), knowledge of antidote, effective drug search route and perception of the need for education and stocking materials about antidotes). Results: It included total 281 hospital pharmacists from 30 hospitals in S. Korea. Of them, only 16.7% have been questioned about drug overdose from patient or representative and 35% have learned about antidotes in case of drug overdose through education program of Korean association of hospital pharmacist or university. About 98% thought that education and stocking materials about frequently overdosed drug and antidotes are helpful for patients in emergent case. Also, the percentage of correct answer of each questions about antidotes were higher in educated group ($p{\leq}0.001$). The more work years are, the percentage of correct answer of each questions are higher ($p{\leq}0.001$). Conclusion: In conclusion, it will be helpful for reducing damage by drug overdose that pharmacists take regular education about antidote for all pharmacist and pharmacy student. In addition, preparing and keeping booklet for Korean Style-antidote in pharmacy is needed currently for protecting public health.

• Restorative Dentistry and Endodontics
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• v.40 no.2
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• pp.128-135
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• 2015

Objectives: This study evaluated the effects of the resin thickness on the microhardness and optical properties of bulk-fill resin composites. Materials and Methods: Four bulk-fill (Venus Bulk Fill, Heraeus Kulzer; SDR, Dentsply Caulk; Tetric N-Ceram Bulk Fill, Ivoclar vivadent; SonicFill, Kerr) and two regular resin composites (Charisma flow, Heraeus Kulzer; Tetric N-Ceram, Ivoclar vivadent) were used. Sixty acrylic cylindrical molds were prepared for each thickness (2, 3 and 4 mm). The molds were divided into six groups for resin composites. The microhardness was measured on the top and bottom surfaces, and the colors were measured using Commission Internationale d'Eclairage (CIE) $L^*a^*b^*$ system. Color differences according to the thickness and translucency parameters and the correlations between the microhardness and translucency parameter were analyzed. The microhardness and color differences were analyzed by ANOVA and Scheffe's post hoc test, and a student t-test, respectively. The level of significance was set to ${\alpha}=0.05$. Results: The microhardness decreased with increasing resin thickness. The bulk-fill resin composites showed a bottom/top hardness ratio of almost 80% or more in 4 mm thick specimens. The highest translucency parameter was observed in Venus Bulk Fill. All resin composites used in this study except for Venus Bulk Fill showed linear correlations between the microhardness and translucency parameter according to the thickness. Conclusions: Within the limitations of this study, the bulk-fill resin composites used in this study can be placed and cured properly in the 4 mm bulk.

• Restorative Dentistry and Endodontics
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• v.47 no.4
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• pp.43.1-43.13
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• 2022

Objectives: This study compared the surface gloss (SG), gloss retention (GR), and color stability (CS) of 2 universal resin composites after chemical (CA) and mechanical (MA) aging. Materials and Methods: Twenty disc-shaped samples of G-ænial A'Chord (GC-Europe) and Filtek Universal (3M-ESPE) were polished with sequential abrasive papers. For CA, specimens were stored in 1 mL of 75% ethanol for 15 days at 37℃, and readings (SG, GR, and CS) were obtained at baseline and 5, 10, and 15 days. For MA, specimens were subjected to 10,750 simulated brushing cycles. SG and CS were evaluated after every 3,583 cycles. SG was measured with a glossmeter (geometrical configuration: 60°), and values were expressed in gloss units. Color was measured with a spectrophotometer using the CIE-L^*a^*b^* color system. The Student's t-test, 1-way analysis of variance, and Scheffé test were used for statistical analysis (α = 0.05). Results: G-ænial presented significantly higher SG values than Filtek (p = 0.02), with GR reductions of 5.2% (CA) and 5.3% (MA) for G-ænial and 7.6% (CA) and 7.2% (MA) for Filtek. The aging protocol had no statistically significant effect on SG or GR (p = 0.25) from baseline to the final readings. G-ænial-MA presented the lowest color difference (ΔE = 1.8), and G-ænial-CA and Filtek-CA had the largest changes (ΔE = 8.6 and ΔE = 11.8, respectively). Conclusion: G-ænial presented higher SG values and better CS. Both restorative materials demonstrated acceptable GR and CS. Aging protocols impacted these properties negatively.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.153-161
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• 2013

Recently, there has been a tremendous increase in the availability of educational materials for foreign language learning. As part of this trend, there has been an increase in the amount of electronically mediated materials available. However, conventional educational contents developed using computer technology has provided typically one-way information, which is not the most helpful thing for users. Providing the user's convenience requires additional off-line analysis for diagnosing an individual user's learning. To improve the user's comprehension of texts written in a foreign language, we propose an intelligent learning tool based on the analysis of the user's eyeball movements, which is able to diagnose and improve foreign language reading ability by providing necessary supplementary aid just when it is needed. To determine the user's learning state, we correlate their eye movements with findings from research in cognitive psychology and neurophysiology. Based on this, the learning tool can distinguish whether users know or do not know words when they are reading foreign language sentences. If the learning tool judges a word to be unknown, it immediately provides the student with the meaning of the word by extracting it from an on-line dictionary. The proposed model provides a tool which empowers independent learning and makes access to the meanings of unknown words automatic. In this way, it can enhance a user's reading achievement as well as satisfaction with text comprehension in a foreign language.

• Journal of Korean Library and Information Science Society
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• v.5
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• pp.119-168
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• 1978

This is a survey of the reserved book system in the pilot universities in Korea. We have surveyed only 22 university libraries among 29 pilot schools as of 1977, because of the differences in the library users, library organization, library facilities, and library materials between universities and colleges. In 1972, the Korean Ministry of Education developed a reformation plan for their higher education based on the teaching method of curriculum-oriented faculty instead of that of the faculty-oriented curriculum. The former puts emphasis on the cultivation of a student's thinking, creativity, and judgement through self-teaching to do a given assignment. The reserved book system in a college or university library is one of the most important methods necessary to accomplish the above educational aim. The survey used a questionnaire with 50 question on 28 items concerning the various aspects of the reserved book system in 22 pilot universities. the survey result discovered many problems needing correction. The following list describes the measures needed to correct the problems found in the pilot universities. 1. The management of a centralized reserved book system is much more effective and economical than the decentralized reserved book system when a university is located on the same campus. 2. In the university library, an independent reserved book department requires to gain the desired educational aims as compared with the reserved book room controlled by any other department in the library. 3. The reserved book system should not be adopted by all the departments at once but enlarged gradually, for it needs the understanding and support of faculty members and the university itself. 4. As competence is essential to the effective operation of the reserved book room, the university library should not place an unqualified person in charge of the reserved book department. 5. The librarian in charge of the reserved book department is required to do more professional works such as analysis of users, collection and analysis of syllabuses, maintenance of faculty member cooperation, establishment of measures to acquire unavailable materials, and drawing up an effective management plan. However, he is spending most of his time in clerical works, that is, non-professional works. 6. Three to five titles of each reserved book are considered reasonable and required materials should be shelved in proportion to the number of students, that is, one copy per eight or ten students if the materials are allowed to lend for two hours at a time. For the supplementary materials, the library needs to place two or three copies per subject. 7. Professors must select reserved books with care so that they can be used year after year. 8. Few universities are asking professors the number of class students and the date when the reserved material will no longer be needed on reserve. 9. The library should gather all the lists of reserved books from every professor at least three to five months before the courses open, because it takes a long time to obtain foreign materials. 10. It is desirable that the reserved book department should collect the lists and prepare the materials with promptness and consistency. 11. Instead of block buying, it is desirable to purchase reserved books at the time the library gets the reserved book list from the professors. The library should also inform faculty members whether it obtained each reserved book or not before the course open. 12. The library should make a copy of materials if a professor requires to reserve an out-of-print book or partial contents of a book, journal, and thesis. 13. An independent budger for reserved books from the budget for general materials is desired. 14. The shelf arrangement of reserved books by courses or professors under the same department is much more preferable than a classified arrangement. 15. While most of the universities adopted the open shelves system for all the reserved books, it is more effective and economical to take a compromise system, that is, closed shelves for requires materials and open shelves for supplementary materials. 18. Circulation of reserved books needs a different system between required materials and supplementary materials: two or three hours and/or overnight loan for the former and two and/or three days loan for the latter. 17. A reserved book room should be open a long time after class so that students can have sufficient time to use the room. 18. The library must take daily and monthly statistic as well as statistics on every aspect of the reserved book system in order that the library ma decide on policy and management of the reserved book room in collaboration with the university. Furthermore, regular reports on the use of the reserved book room should be made to the president and the executive council by the library to acquire their understanding and cooperation for the reserved book system. 19. Cooperation of faculty members is indispensable to the effective management of the reserved book department and it is desirable to make a committee which will fix various decisions about the system. Whenever the director of the library make his decision, he must consult with his staff in order to involve them earnestly in the operation of the system.

• School Mathematics
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• v.13 no.3
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• pp.501-524
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• 2011

The purpose of this study was to develop teaching-learning materials for informal activities geared toward teaching the nature and structure of proof, to make a case analysis of the application of the developed instructional materials to students in an elementary gifted class, to discuss the feasibility of proof education for gifted elementary students and to give some suggestions on that proof education. It's ultimately meant to help improve the proof abilities of elementary gifted students. After the characteristics of the eight selected gifted elementary students were analyzed, instructional materials of nine sessions were developed to let them learn about the nature and structure of proof by utilizing informal activities. And then they took a lesson two times by using the instructional materials, and how they responded to that education was checked. An analysis framework was produced to assess how they solved the given proof problems, and another analysis framework was made to evaluate their understanding of the structure and nature of proof. In order to see whether they showed any improvement in proof abilities, their proof abilities and proof attitude were tested after they took lessons. And then they were asked to write how they felt, and there appeared seven kinds of significant responses when their writings were analyzed. Their responses proved the possibility of proof education for gifted elementary students, and seven suggestions were given on that education.