• Journal of Korean Ophthalmic Optics Society
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• v.19 no.1
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• pp.99-104
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• 2014

Purpose: This study was to investigate the functional improvement in peripheral vision following eccentric viewing training. Methods: 14 subjects with normal vision took a part with their right eye, peripheral retinal which is $20^{\circ}$ lateral area from the fovea was examined for contrast sensitivity(CS). Eccentric viewing training was performed for 21days with an hour image viewing and examination was repeated. Results: The critical durations for 0.7 cpd were increased 2.67(467 ms) for pre-eccentric viewing training to 2.79(616 ms) for post-eccentric viewing training (p>0.05). The critical durations for 3.0 cpd were also increased 2.53(341 ms) for pre-eccentric viewing training to 3.04(1102 ms) for post-eccentric viewing training (p>0.05). Conclusions: It is recommended to use higher spatial frequency with higher CS for eccentric viewing training and to train more frequently for a short time. Moreover, the study on Korean standardizing of the visual rehabilitation for low vision based on the etiology is sorely required.

• Journal of the Korean Society for information Management
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• v.17 no.4
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• pp.207-227
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• 2000

Recenily, major internalional STM(Science, Trchnical, and Mcdivine) Publichers have been developing prototype systems that can provide the refeence linking of jouinal articles within the scholarly literature on a cross-publisher basis using the URN(Universal Resouree Name). In Korea, it is hard to find the efforts to link the scattered digitalized documents to an individual user through a unified web. In this study, a linking model for an inergrated gatewny fro, bibliographic information to full tcxt has been desugned and 'Electronic Research Resourced Linking system (E3R/LS)' has been developed as a prototype for centralized static reference linking system. There are three major components for constructing refrernce linking systems. The firsl componcnt the Digital Object Identifiet(DO1). is introduced as the public identifier inrended to be applied wherever thr item needs to be identified. For denl~iymg Korean journal articles, llie extended SICI(Serlal Ilem and Conlribut~on Idealifier) has becn newly dehed in 1111s study and is used as a suiiia on DOI. The reierence datubasc conlams the second com~onenl, metadiltil, linkcd to implemenied by all information providers. The CnRI resolution system is used for resolving a DOI into a URL as the third component.

• Korean Journal of Plant Tissue Culture
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• v.28 no.5
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• pp.263-271
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• 2001

Inoculated anthers of Capsicum annuum L. were subjected to 4 and 32$^{\circ}C$ pretreatment and their influence on the microspore viability, early cytological changes and the induction frequency of microspore embryo was investigated. Viability of freshly isolated microspores was between 62 and 64%. During temperature pretreatment, microspore viability showed a rapid decrease and this tendency enhanced with the 32$^{\circ}C$ pretreatment. Irrespective of temperature pretreatment, microspore viability declined to nearly zero after nine days. Before temperature pretreatment, most of the microspores in anthers were at late uninucleate stage. Several types of multinuclear microspores appeared from the 2 day after culture onwards, together with many degenerated and non-induced microspores. The 32$^{\circ}C$ pretreatment gave higher proportions of embryogenic microspore than other treatment. However, the temperature pretreatment had no clear effect on the frequencies of symmetrical binucleate rnicrospore. The multinucleate grains might originate either by symmetrical or asymmetrical division. After 2 days of pretreatment at 25 and 32$^{\circ}C$ , degenerated microspore increased above 50%. In contrast, during 4$^{\circ}C$ treatment, nucleus of most microspores remained intact for 14 days. The 32$^{\circ}C$ pretreatment produced more embryos than 4$^{\circ}C$ treatment. The most effective period of 32$^{\circ}C$ pretreatment was 4 days. In contrast, effective period of 4$^{\circ}C$ pretreatment was 2 days and longer time had deleterious effect on induction of microspore embryo.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.23-32
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• 2007

Variable message sign (VMS), which is used for providing real-time information on traffic conditions and incidents, is one of the important components of intelligent transportation systems. VMS messages need to meet the requirements with the consideration of human factors that messages should be readable and understandable while driving. This study developed a legibility distance model for VMS messages using in-vehicle differential global positioning data (DGPS). Traffic conditions, highway geometric conditions, and VMS message characteristics were investigated for establishing the legibility model based on multiple linear regression analysis. The height of VMS characters, speed, and the number of lanes were identified as dominant factors affecting the variation of legibility distances. It is expected that the proposed model would play a significant role in designing VMS messages for providing more effective real-time traffic information.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.39-47
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• 2008

With dramatic development of IT technology and start of DMB service, installing the DMB equipment in a vehicle for watching TV programs and literal or pictorial traffic information are increasing. Watching the DMB during driving the vehicle could cause visual and cognitive distraction to drivers as much as eating food, operating radio and using mobile phone. However, there is not much empirical research for this topic and no research examined the effect of watching the DMB on driving behaviors in Korea. So, the present study examined the effect of watching the DMB on the driving behaviors with car simulator experiment. Within subject design was used in the study. That is, all subjects drove the vehicle both in the watching DMB condition and the non-watching DMB condition. The results indicated that subjects in the watching DMB condition took longer time to arrive at the destination and operated accelerator and brake pedal rapidly than subjects in the non-watching DMB condition. That is, their overall driving stability was lower than non-watching subjects'. Additionally, we examined the difference among the DMB control conditions (i.e., keypad condition, touch-pad condition and remote controller condition) in the driving behaviors. Finally, we discussed the limitations and the implications of the present study.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.4
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• pp.329-334
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• 2006

The depth distributions of total $^3H$ and $^{14}C$ activities were characterized for the activated shielding concrete from a decommissioning of KRR-2 using the commercially available tube furnace and a liquid scintillation counter. The correlation of measurement results between $^3H,\;^{14}C$ and gammer emitter was evaluated to apply for estimating radionuclide inventory of the concrete waste generated from decommissioning KRR-2. The detection limits for $^3H$ and $^{14}C$ are 0.048 and 0.028 Bq/g respectively. The specific activities of the $^3H$ and $^{14}C$ tend to decrease exponentially as the depth of the concrete becomes deeper from the surface. In addition, the $^3H$ and $^{14}C$ activities were in good correlation with the $^{60}CO$ activities analysed for the shielding concrete of KRR-2.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.2
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• pp.97-105
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• 2014

In the case of the direct measurement of $^{226}Ra$ using a HPGe gamma-ray spectrometer, the interference between gammarays with 186.21 keV of $^{226}Ra$ and 185.7 keV of $^{235}U$ should be corrected to calculate the net peak area in the energy spectrum. In general, it is very difficult to conduct peaks stripping with difference of about 0.5 keV, although a HPGe with the superior resolution is applied and the maximum channels is applied to the spectrometer. In this study, several interference correction techniques in the direct measurement were surveyed to evaluate the feasibility for the measurement of $^{226}Ra$ using the gamma-ray spectrometery. Applying the interference corrections to the analysis of raw materials and by-products, the method validation for the direct measurement of $^{226}Ra$ was conducted by evaluating the measurement uncertainty, linearity, and range. As a result, the optimum method of the interference correction was selected by comparing with the indirect measurement of which progenies of $^{226}Ra$, such as $^{214}Pb$ and $^{214}Bi$, were analyzed in the secular equilibrium state.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.1
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• pp.1-22
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• 2010

The purpose of this study was to examine the relationship between teacher's role and interaction patterns in mathematics classrooms. Teacher's role was divided into usual practices with students, usual practices with content and usual practices with students and contents, and interaction patterns were classified into report, inquiry and discussion. The subjects in this study were teachers and students in three fourth- grade classes in T elementary school located in Seoul. After the classes of every math teacher were observed, three teachers who played distinctively unique roles were selected in accordance with the results of the first-semester autonomous supervision, of open class for parents and of the instructional observation. Thus, there was a close relationship between the teacher roles and interaction patterns. And it's concluded that students are able to have a more discussion on each other's ideas in the student-centered classroom, and that teachers should perform active roles in that process. Given the findings of the study, there are some suggestions: First, the teachers appeared to fulfill consistent roles when their videotaped classes, study aids and performance assessment materials were analyzed, and they should play more active roles in mathematics class. Second, they should try to create the kinds of climate that encourages students to come up with ideas in an active manner. Third, earlier studies had focused on student-teacher interaction patterns, but this study found that the roles of the teachers depended on interaction with not only students but study aids and performance assessment materials, and that the interaction patterns hinged on their roles as well. Therefore more profound research efforts should be directed into this issue.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.3
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• pp.937-957
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• 2010

The purpose of this study is to discover the features of symbol sense. This study tries to sum up the meaning and elements of symbol sense and the measures to improve them through documents. Also based on this, it analyzes the learning conditions about symbol sense for 6th grade mathematically able students and suggests the method that activates symbol sense in the math of elementary schools. Considering various studies on symbol sense, symbol sense means the exact knowledge and essential understanding in a comprehensive way. Symbol sense is an intuition about symbols that grasps the meaning of symbols, understands the situation of question, and realizes the usefulness of symbols in resolving a process. Considering all other scholars' opinions, this study sums up 5 elements of the symbol sense. (The recognition of needs to introduce symbol, ability to read the meaning of symbols, choice of suitable symbols according to the context, pattern guess through visualization, recognize the role of symbols in other context) This study draws the following conclusions after applying the symbol questionnaires targeting 6th grade mathematically able students : First, although they are math talents, there are some differences in terms of the symbol sense level. Second, 5 elements of the symbol sense are not completely separated. They are rather closely related in terms of mainly the symbol understanding, thereby several elements are combined.

• School Mathematics
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• v.18 no.1
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• pp.143-157
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• 2016

North Korea had been reorganized its educational curriculum and new contexts were authored in 2013. In this study, mathematics contexts of North Korean secondary school's first grade in 2009 and 2013 were investigated. And the changes of content structure, content development, and content composition were analyzed. Results were as follows: First, with respect to the content structure, 1 chapter decreased, while lesson number was intact and 4 subunits increased. Second, with respect to the content development, considerable changes were presented. The tendencies that encouraged student and pursued a student friendly form were investigated. Third, with respect to the content composition, obvious changes were presented. It was investigated that the ratio of numbers and number operations, letters and expressions decreased nearly half. And new contents were supplemented in the areas of patterns, geometry, functions, probability and statics, equation of figures, set and statement. This changes suggests that differences between contexts of South and North Korea is narrowing compared to the past. In conclusion, the direction of North Korean mathematical education is changing for the general direction of South Korean mathematical education.