• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.15 no.3
• /
• pp.265-279
• /
• 2017

The Gyeongju underground silo type disposal facility, approved for use in December 2014, is in operation for the disposal of low and very low-level radioactive wastes, excluding intermediate-level waste. That is why the existing low-level radioactive waste level has been subdivided and the concentration limit value for intermediate-level waste has been changed in accordance with Nuclear Safety Commission Notice 2014-003. For the safe disposal of intermediate-level wastes, new optimization methodology for calculating the concentration limit of intermediate radioactive level wastes at an underground silo type disposal facility was developed. According to the developed optimization methodology, concentration limits of intermediate-level wastes were derived and the inventory of radioactive nuclides was evaluated. The operation and post closure scenarios were evaluated for the derived radioactive nuclide inventory and the results of all scenarios were confirmed to meet the regulatory limit. However, in case of $^{14}C$, it was confirmed that additional radioactivity limitation through a well scenario was needed in addition to the limit of disposal concentration. It was confirmed that the derived intermediate concentration limit of radioactive waste can be used as the intermediate-level waste concentration limit for the underground disposal facility. For the safe disposal of intermediate-level wastes, KORAD plans to acquire additional data from the radioactive waste generator and manage the cumulative radioactivity of $^{14}C$.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.20 no.3
• /
• pp.365-369
• /
• 2022

Operating and decommissioning nuclear power plants generates radioactive waste. This radioactive waste can be categorized into several different levels, for example, low, intermediate, and high, according to the regulations. Currently, low and intermediate-level waste are stored in conventional 200-liter drums to be disposed. However, in Korea, the disposal of intermediate-level radioactive waste is virtually impossible as there are no available facilities. Furthermore, large-sized intermediate-level radioactive waste, such as reactor internals from decommissioning, need to be segmented into smaller sizes so they can be adequately stored in the conventional drums. This segmentation process requires additional costs and also produces secondary waste. Therefore, this paper suggests repurposing the no-longer-used spent nuclear fuel casks. The casks are larger in size than the conventional drums, thus requiring less segmentation of waste. Furthermore, the safety requirements of the spent nuclear fuel casks are severer than those of the drums. Hence, repurposed spent nuclear fuel casks could better address potential risks such as dropping, submerging, or a fire. In addition, the spent nuclear fuel casks need to be disposed in compliance with the regulations for low level radioactive waste. This cost may be avoided by repurposing the casks.

• The Korean Journal of Ecology
• /
• v.21 no.3
• /
• pp.233-241
• /
• 1998

In order to test of intermediate disturbance hypothesis that an intermediate level of disturbance maximize biodiversity and to elucidate the effect of disturbance during the early old-field succession, the response of plant community along an experimental disturbance gradient was investigated in a five-year old-field. Response of plant community along an experimental disturbance gradient was connected with light condition because artificial disturbance gradient had been treat by clipping of plants and removing of litter. Artificial disturbance in five-year old-field plant community retarded rate of succession by increasing invasion and performance of the earlier successional species in the initial and middle stage of disturbance treatment. The species richness in the blocks of intermediate disturbance level showed the peak in early and mid-summer. This result did correspond with the prediction of intermediate disturbance hypothesis.

• Genomics & Informatics
• /
• v.20 no.3
• /
• pp.34.1-34.11
• /
• 2022

Multilevel analysis is an appropriate and powerful tool for analyzing hierarchical structure data widely applied from public health to genomic data. In practice, however, we may lose the information on multiple nesting levels in the multilevel analysis since data may fail to capture all levels of hierarchy, or the top or intermediate levels of hierarchy are ignored in the analysis. In this study, we consider a multilevel linear mixed effect model (LMM) with single imputation that can involve all data hierarchy levels in the presence of missing top or intermediate-level clusters. We evaluate and compare the performance of a multilevel LMM with single imputation with other models ignoring the data hierarchy or missing intermediate-level clusters. To this end, we applied a multilevel LMM with single imputation and other models to hierarchically structured cohort data with some intermediate levels missing and to simulated data with various cluster sizes and missing rates of intermediate-level clusters. A thorough simulation study demonstrated that an LMM with single imputation estimates fixed coefficients and variance components of a multilevel model more accurately than other models ignoring data hierarchy or missing clusters in terms of mean squared error and coverage probability. In particular, when models ignoring data hierarchy or missing clusters were applied, the variance components of random effects were overestimated. We observed similar results from the analysis of hierarchically structured cohort data.

• Journal of Korean language education
• /
• v.29 no.3
• /
• pp.145-163
• /
• 2018

The purpose of this study was to identify the necessity of research for increasing French language learners and to examine their use of listening strategies according to their proficiency as a basic study for their continuous learning and communication skills. In the case of French language Korean learners, both the beginner and intermediate learners used the upper cognitive strategy most frequently. However, the cognitive strategy, which has been mentioned as a frequently used strategy in previous studies, was found to be the least used in this study. This finding can be attributed to differences in mores and mastery of prior studies and research subjects. The cognitive strategy was lower in both the beginner and intermediate levels, but the level of use increased significantly in the intermediate level compared to the beginner level, showing only statistically significant differences in the usage patterns according to the proficiency level among the four listening strategies.

• International Journal of Computer Science & Network Security
• /
• v.22 no.5
• /
• pp.266-276
• /
• 2022

The study aimed to pinpoint the effects of an educational environment based on gamification on developing achievement motivation among first-grade intermediate students. Using an achievement motivation scale, the study adopted a quasi-experimental design with experimental and control groups. The sample consisted of 52 students selected randomly from the first-grade intermediate students. They were studying in public intermediate schools in Jeddah at the time of this study. They were divided into two groups. The control group (n=24 respondent), and the experimental group (n=28 respondent). The results showed statistically significant differences at the level α ≥ 0.05 between the mean scores of the experimental group and the control group in the posttest of the achievement motivation measurement in favor of the experimental group. The study recommended using gamification in designing computer curricula and courses across educational stages in Saudi Arabia. It also recommends training the computer and information technology teachers on using gamification in their teaching.

• Cross-Cultural Studies
• /
• v.20
• /
• pp.67-111
• /
• 2010

This paper examined the role of intermediate texts in the writing process in the context of an EFL composition class. From the tradition of teacher research, this study examined how the Korean college students in different proficiency groups created intermediate texts and used them while composing their own writing. The students produced various types of intermediate texts during the compositing process, which could serve as a basis of their writing. However, the patterns of using these intermediate texts differed widely across the proficiency groups. A writing cycle for the low proficiency group, or "surface reading-few intermediate texts-writing," indicates that less proficient students tended to engage in reading in separation of writing practices and thus produced few intermediate texts through their literacy practices. On the other hand, the students in the higher proficiency groups revealed the more integrated pattern (i.e., purpose reading/intermediate texts/writing), indicating that they often engaged in reading with specific writing purposes, practiced reading in connection to other writing practices, and elaborated written intermediate texts produced. This study argues that, to shift our student writers to a higher level category, we as teachers need to help them engage in reading and writing practices in the way they produce and use intermediate texts appropriate to their specific writing purposes.

• Communications for Statistical Applications and Methods
• /
• v.15 no.5
• /
• pp.727-735
• /
• 2008

Consider a clinical trial in which the main end-point is survival. Suppose after the start of the study an intermediate event occurs which may be influenced by a covariate(or treatment). In many clinical studies the occurrence of an intermediate event may change the survival distribution. This investigation develops two-stage model which, in the first stage, models the effect of covariate on the intermediate event and models the relationship between survival time and covariate as well as the intermediate event. In this paper, the two-stage model is presented in order to model intermediate event and a test based on this model is also provided. A numerical simulations are carried out to evaluate its overall significance level.

• Journal of the Korean School Mathematics Society
• /
• v.1 no.1
• /
• pp.139-149
• /
• 1998

The purpose of this study is to check out whether the method that students make problems and anouence them to both students and teacher in the next class influence on the students' intersts, attitudes, logical thinking ability and lerning achievement in mathematics. The following is the experimental design and procedure. First, the author divided students into two groups. One is the experimental group and the other is the control group. These two groups' students consist of the advanced level, the intermediate level and the elementary level according to the students' learning proficiency Second, the author used the different teaching method between the experimental group and the control group. The author gave the experimental group's students the learning assignment problems according to their three levels and made students present the problems to the instructor and classmates in the next class. On the other hand, the author gave the control group's students learning assignment problems according to their three levels, and made them only submit their assingment to the instructor. The results of this study are as follows : 1)The method of solving and presenting the self-made problems on the basis of the informations to solve the given preceding model learning problems according to students' levels made students' learning attitudes more positive even though the method couldn't enhance the students' interests in mathematics. 2)The method of solving and presenting the self-made problems was effective to improve the logical thinking ability for especially the intermediate level's students among the three levels. In addition, the intermediate level's students showed great positive changes in their improvements of the learning achievment. It is assumed that this result is caused by two major factors(reasons). One is students' confidence that they can solve the fundamental problems without difficulty. And the other is students' desire to solve the problems of the intermediate level or more advanced level.

• Nuclear Engineering and Technology
• /
• v.40 no.6
• /
• pp.511-516
• /
• 2008

Korea Hydro & Nuclear Power Co., Ltd. (KHNP) developed new IP-2 packages to transport low- and intermediate-level radioactive waste (LILW) steel drums from nuclear power plants to a disposal facility in accordance with IAEA and Korean transport regulations of radioactive material. Radiation shielding evaluation of the packages was carried out to demonstrate compliance with the regulatory requirements for IP-2 packages of radioactive material. Dose rate limits of LILW drums contained in the packages were determined.