• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.3
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• pp.275-279
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• 2023

La_0.7Sr_0.3-xMg_xMnO₃ (LSMMO) (x=0.05~0.20) specimens are fabricated by a solid phase sintering method, and the sintering temperature and time are 1,300℃ and 2 hours, respectively. The dependence of the crystalline structure according to the amount of Mg²⁺ contents is not observed, and all specimens show a polycrystalline rhombohedral crystal structure, the X-ray diffraction (110) peaks move to the high angle side with increasing the amount of Mg²⁺ contents. LSMMO specimens exhibit a granule-shaped microstructure with an average grain size of 1 ㎛ or less. Resistivity gradually decrease as the amount of Mg²⁺ contents increased. And in the La_0.7Sr_0.1Mg_0.2MnO₃ specimen, resistivity and B_25/65-value are 36.7 Ω-cm and 394 K at room temperature, respectively. LSMMO specimens show a variable-range hopping (VRH) electrical conduction mechanism, and the negative temperature of coefficient of resistance (NTCR) is approximately 0.37~0.38%/℃.

• Journal of Intelligence and Information Systems
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• v.19 no.4
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• pp.81-96
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• 2013

Video information retrieval has become a very important issue because of the explosive increase in video data from Web content development. Meanwhile, content-based video analysis using visual features has been the main source for video information retrieval and browsing. Content in video can be represented with content-based analysis techniques, which can extract various features from audio-visual data such as frames, shots, colors, texture, or shape. Moreover, similarity between videos can be measured through content-based analysis. However, a movie that is one of typical types of video data is organized by story as well as audio-visual data. This causes a semantic gap between significant information recognized by people and information resulting from content-based analysis, when content-based video analysis using only audio-visual data of low level is applied to information retrieval of movie. The reason for this semantic gap is that the story line for a movie is high level information, with relationships in the content that changes as the movie progresses. Information retrieval related to the story line of a movie cannot be executed by only content-based analysis techniques. A formal model is needed, which can determine relationships among movie contents, or track meaning changes, in order to accurately retrieve the story information. Recently, story-based video analysis techniques have emerged using a social network concept for story information retrieval. These approaches represent a story by using the relationships between characters in a movie, but these approaches have problems. First, they do not express dynamic changes in relationships between characters according to story development. Second, they miss profound information, such as emotions indicating the identities and psychological states of the characters. Emotion is essential to understanding a character's motivation, conflict, and resolution. Third, they do not take account of events and background that contribute to the story. As a result, this paper reviews the importance and weaknesses of previous video analysis methods ranging from content-based approaches to story analysis based on social network. Also, we suggest necessary elements, such as character, background, and events, based on narrative structures introduced in the literature. We extract characters' emotional words from the script of the movie Pretty Woman by using the hierarchical attribute of WordNet, which is an extensive English thesaurus. WordNet offers relationships between words (e.g., synonyms, hypernyms, hyponyms, antonyms). We present a method to visualize the emotional pattern of a character over time. Second, a character's inner nature must be predetermined in order to model a character arc that can depict the character's growth and development. To this end, we analyze the amount of the character's dialogue in the script and track the character's inner nature using social network concepts, such as in-degree (incoming links) and out-degree (outgoing links). Additionally, we propose a method that can track a character's inner nature by tracing indices such as degree, in-degree, and out-degree of the character network in a movie through its progression. Finally, the spatial background where characters meet and where events take place is an important element in the story. We take advantage of the movie script to extracting significant spatial background and suggest a scene map describing spatial arrangements and distances in the movie. Important places where main characters first meet or where they stay during long periods of time can be extracted through this scene map. In view of the aforementioned three elements (character, event, background), we extract a variety of information related to the story and evaluate the performance of the proposed method. We can track story information extracted over time and detect a change in the character's emotion or inner nature, spatial movement, and conflicts and resolutions in the story.

• Journal of Labour Economics
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• v.30 no.2
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• pp.1-31
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• 2007

The purpose of this paper is to analyse wage differentials between non-regular and regular works. Data from EAPS(Economically Active Population Survey) 2005 show that the monthly wage level of non-regular worker is only 63% of regular worker and thus there exist 37% wage differentials. However, these wage differentials do not control for hours of work, the amount of human capital, job characteristics, and other individual characteristics affecting wages. If these variables are added to the hourly wage regression equation, the wage gap between non-regular and regular workers drastically decreases to 2.2%. Furthermore, decomposition of the wage differentials by Oaxaca method shows that productivity difference between non-regular and regular workers explains up to 91% of the wage gap. This implies that the magnitude of wage discrimination against non-regular workers is at most 0.2% of hourly wage of regular workers. To control for unobserved individual heterogeneities more accurately, we also construct panel data and estimate wage differentials. The results from the panel data approach show that there is no difference in the hourly wages between non-regular and regular workers. In some specifications, the wage rate of non-regular worker is rather higher than that of regular worker. These results are consistent with economic theory. Other things being equal, workers with unstable employment may require higher wages to compensate their unstability. Firms are willing to pay higher wages if they can get more flexibility from non-regular employment. Empirical results in this paper cast doubt on the view that there is wage discrimination against non-regular workers in the labor market. Public policies should be targeted for disadvantaged groups among non-regular workers, not for non-regular workers in general.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.310-318
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• 2013

In territorial ecosystem, soil has stored considerable amount of carbon, and it is vulnerable to weakness release much of the carbon to atmosphere. In this study, we have been effort realization and discussion to the error between inter-instruments and measurement methods, time and special variations, gap filling and separation from each source included in soil respiration, used to collect soil respiration data in various ecosystems in Korea. In conclusion, it have to collect calibration data throughout comparison test between methods and instruments because accumulated data from past and accumulating data in present did not calibrated. In predicting change of soil carbon dynamic using the model method, it needs important data such as longterm and short-term data, artificial handling data of major factor, data from various ecosystem, soil texture, soil depth etc. In company with, we should collect highly qualified data through deep consideration of present problems.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.4
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• pp.302-309
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• 2017

If a hydrogen explosion occurs in a containment building, its multiplex defense wall may be destroyed and a large amount of radioactive material may be released. The hydrogen occurred interacting with melting fuel rods must be effectively controlled and removed. however, the countermeasures for reducing explosion risk are difficult to carry out, due owing to the various variety of accident scenarios causes and the irregularity of hydrogen distribution and behavior. In this study, We examine the guide structures while considering the ambient flows, in order to improve the efficiency of PAR the widely used Passive Autocatalytic Recombiner(PAR). We simulate the fluid behavior and the hydrogen reduction rate were simulated when a guide is attached to the two-step catalyst PAR. For an upward flow, the consisting of a height of 150mm, a gap of 0mm, and a performs $60^{\circ}$ showed the best. In contrast, for a sideways flow, a consisting of the height of 150mm, a gap of 100mm, and a performs $60^{\circ}$ showed the best in the case of side ward flow. for a downward flow, a consisting of the height of 50mm and a directly attached guide produce the best in the case of down ward flow results.

• Journal of Conservation Science
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• v.27 no.3
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• pp.323-332
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• 2011

Microtexture and components of 7 glass bead fragments excavated from Andong tumulus in Gildu-ri, Goheung have been analyzed to determine the characteristics of their weathered condition as well as chemical compositions. Firstly, status of microtexture shows that there is a large quantity of pollutants which were presumably transferred from the buried environment into the surface and the gap of the cracks. The examination has displayed that there are less amount of alkali metal components such as sodium (Na) and potasium (K) in the gap of the cracks than on the surface. The chemical compositions analysis has confirmed that two samples belongs to potash glass group ($K_2O-SiO_2$), four to soda glass group ($Na_2O-SiO_2$), and one to the mixed alkali glass group. Chromophoric elements of the glass varies by different colours: blue and navy are cobalt (Co); greenish blue is copper (Cu) and iron (Fe); and light brown is Fe respectively. Such kind of scientific analysis of the excavated glass beads will contribute to the understanding of interchange between various local cultures and arts within the southwest region of Korean Peninsula during the 4th and the 5th centuries.

• Korean Journal of Materials Research
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• v.1 no.4
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• pp.221-228
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• 1991

In this study we have investigated the sealing characteristics of glasses suitable for producing the magnetic gap of the ferrite head cores which have been widely used for VTR and computer magnetic heads. $PbO-B_2O_3$ g1asses were evaluated by measuring microhardness, thermal expansion coefficient and sliding wear resistance. Concentration distribution of elements at the interface was observed by WDS. wettability was measured by high temperature microscopy. The results were as follows ; 1. In sealing glasses of $PbO-B_2O_3$ system, thermal expansion coefficient and wear volume were increased with increasing PbO content, and were decreased with increasing $B_2O_3$ content. 2. The contact angle of $PbO-B_2O_3$ Systems was mainly influenced by PbO content. 3. The sealing temperature showed a tendency to decrease proportionally with the increase of the coefficient of thermal expansion. 4. The diffusion at the interface between Mn-Zn single crystal ferrite and sealing glasses of $PbO-B_2O_3$ system was dominated by small amount of diffusion of ferrite content into glass part, which was very little affected by sealing heat treatment time.

• Journal of Elementary Mathematics Education in Korea
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• v.19 no.4
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• pp.485-499
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• 2015

In this paper, focusing on definitions of terms related to ratio (a:b, external ratio, internal ratio, percentage, proportion, bi-ui-gap(value of a:b)), elementary school mathematics textbooks of Korea and Japan are compared. We can find significant differences between Korean and Japanese textbooks. In Korean textbook, 'bi-yul' includes both of the internal ratio and the external ratio. In Japanese textbooks, the external ratio(amount of unit size) and the internal ratio(wariai) are defined independently. And a:b is set to a subconcept of the internal ratio. In addition, a:b and percentage are presented as methods to express the internal ratio. From these results, the following four implications for developing our mathematics textbooks can be presented as conclusions. First, it is necessary to limit the ratio to mean the internal ratio. Second, it is necessary to define connotatively the ratio as the internal ratio and to set it as a prior concept of a:b. Third, it is necessary to define 1% as the internal ratio 0.01. Fourth, it is necessary to define bi-ui-gap as a number for expressing a:b, when viewing a:b as the expression method of the internal ratio.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.3
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• pp.313-319
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• 2019

The A-KRS (Advanced Korean Reference Disposal System) is the disposal concept for pyroprocessed waste, which has been developed by the Korea Atomic Energy Research Institute. In this disposal concept, the amount of high-level radioactive waste is minimized using pyrochemical process, called pyroprocessing. The produced pyroprocessed waste is then solidified in the form of monazite ceramic. The final product of ceramic wastes will be disposed of in a deep geological repository. By the way, the decay heat is generated due to the radioactive decay of fission products and raises the temperature of buffer materials in the near field of radioactive waste repository. However, the buffer temperature must be kept below $100^{\circ}C$ according to the safety regulation. Usually, the temperature can be controlled by variation of the canister interdistance. However, KAERI has modelled thermal analysis under the boundary condition, where the waste canisters are in direct contact with each other. Therefore, a reliable temperature analysis in the disposal system may fail because of unknown thermal resistence values caused by the spatial gap between waste canisters. In the present work, we have performed thermal analyses considering the gap between heating elements and canisters at the beginning of canister loading into the radioactive waste repository. All thermal analyses were performed using the COMSOL software package.

• Korean Journal of Community Nutrition
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• v.26 no.1
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• pp.37-47
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• 2021

Objectives: The purpose of this study was to discover the changes in obesity prevalence and dietary habits in Korean adults residing in various residential areas during the last 10 years. Methods: Data on Korean adults aged 19 years and above was obtained from the 4th (2007-2009) and the 7th (2016-2018) Korea National Health and Nutrition Examination Survey. The subjects were classified into metropolitan (4th: n=5,977, 7th: n=6,651), urban (4th: n=4,511, 7th: n=5,512) and rural (4th: n=3,566, 7th: n=2,570) based on their residence. The general characteristics, nutrient intake, intake amount, food groups, and healthy dietary factors were analyzed. The association between residential areas and obesity prevalence were analyzed by multiple logistic regression. Results: In urban and rural areas, the obesity rate increased in the 7th survey compared to the 4th survey, excluding the metropolitan area. The carbohydrate intake decreased, and lipid intake increased in the 7th survey compared to the 4th survey. Over the same period, the intake of cereals and vegetables decreased, and the intake of meat and processed foods increased. Rural residents had a higher intake of cereals and vegetables, and a lower intake of milk and processed foods than those in metropolitan areas and urban residents. The proportion of subjects who practiced a healthy diet increased in the 7th survey compared to the 4th survey. In the 4th survey, there was no relationship seen between the prevalence of obesity and the subject's residential area, but in the 7th survey, the odds ratio of obesity was higher in rural areas than in the metropolitan areas, confirming the regional gap (OR: 1.16, 95% CI=1.00-1.36, P=0.044). Conclusions: This study showed that the obesity prevalence increased in rural residents compared to metropolitan residents, indicating a gap between the regions. The nutrient intake and intake of food groups changed in the 10 years under consideration, and there were differences seen between regions. Therefore, it is necessary to formulate a policy that will reduce obesity prevalence and health inequalities between regions.