• Journal of Radiation Protection and Research
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• v.22 no.3
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• pp.161-170
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• 1997

Theoretical and experimental determination of the lower limits of detection (LLD) of C-300-A $CaSO_4$:Dy TL dosimeters which are currently used for the personnel monitoring in Korea Atomic Energy Research Institute(KAERI) are described with a critical level which is defined as the signal level above which a result has a probability of being due to a fluctuation of the background. The personnel monitoring processors can derived easily the LLD of their system using this method with the background readings of their service interval and the irradiation readings of the known doses. Experimental studies were also conducted for the fading rates of the dosimeters with the temperatures and humidities for 3 months. Finally sensitivity changes in repeat uses were measured for 40 times consecutive uses of the dosimeters. The applications of the experimental results of fading rates and sensitivity changes in real personnel monitoring services are discussed briefly.

• Journal of The Korean Association For Science Education
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• v.8 no.1
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• pp.1-22
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• 1988

The educational policy of a nation should be based on the results of nation-wide studies and their analyses. This study is the third one in a series of research on "development of improvement plan and monitoring system for secondary school science", focusing on the three major areas, such as students' achievements, science instruction and conditions for science education in vocational high schools. In general, the results showed that science achievements in vocational high schools were significantly lower than those of general high schools. While the achievement level in physics was lower by one percent, the achievement levels in chemistry and biology were significantly lower by more than 5 percents. In the case of scientific inquiry, the results showed much lower scores compared to those of general high schools. Concerning the inquiry abilities, most of the students did not possess the formal operational thinking skills such as controlling variables and combinatorial thinking. The ability of experimental skills seemed to be closely related to the students' majors. Students in industrial arts schools could measure electric resistance very well, while students in agricultural high school students failed completely. In the area of students' attitude toward science, the greater part of the students had the experiences of using scientific equipments (68.6 %), experimentation (54.3 %), and extracurricular science activities (56.9 %). They also showed positive attitude towards the nature of science (59.8%). The results of the survey on science instruction and school conditions for science education showed the needs for improvement In general, the priority of science education in vocational high schools was very low compared to their major subjects. The teachers as well as students thought science text books nor to be difficult These responses and the low achievement levels seemed to be contradictory to each other. The facilities for science experiments were better equipped and installed to general high schools. However. the lack of budget was a major problem for performing experiments uning the facilities. Therefore. science education in vocational high school have many things to be improved For the improvement of science education in vocational high schools, financial support as well as the intention for the improvement must be the essential factors.

• Korean Journal of Social Welfare
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• v.62 no.3
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• pp.219-245
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• 2010

The objective of this study is to identify the community living experiences of married immigrant women in rural areas. For this purpose, we conducted qualitative research by sampling 14 married immigrant women who had lived in Korea for over three years by having in depth interviews with them. This study employed the grounded theory method suggested by Strauss and Corbin(1998). When raw data from in depth interviews with the participants were processed by open coding through the continuous comparison method with theoretical sensitivity, a total of 13 categories, 27 sub.categories, and 71 concepts were extracted. In case of axial coding, according to the results of analyzing through the paradigm procedure, the causal conditions for the community living experiences of married immigrant women in rural areas were 'Uncertain start' and 'Confront practical problems,' and the central phenomenon was 'Search for existence to participate in community activities.' Contextual conditions affecting the phenomenon was 'Regret international marriage,' 'Experience conflicts,' and 'Look with negative prejudices,' 'Overcome the actual' and action/interaction strategies were 'Look for a breakthrough of life' and 'Manage to acceptance.' Intervening conditions for promoting or suppressing the action/interaction strategies for the central phenomenon were 'Social support system' and 'local limitations,' and as a result, the community living experiences of married immigrant women in rural areas appeared to 'Prepare the future,' 'Hope continuous social activities,' and 'Expect public support systems.'

• Tuberculosis and Respiratory Diseases
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• v.57 no.2
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• pp.148-159
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• 2004

Background : This study was conducted to evaluate the survival benefit of the bronchial arterial embolization (BAE) for patients presenting with non-traumatic hemoptysis. Methods : The clinical data were retrospectively collected from the medical records and the Order Communicating Systems (OCS). The information dealing with death was collected from national death certificates. After enrolled patients were divided with two group such as BAE group (patients who were managed with BAE) and non-BAE group (patients who were managed with conservative modality), the survival benefit of BAE was estimated during the observational period of 24 months through using the Kaplan-Meier survival graph and the Cox-proportional hazard regression analysis. Results : The number of total cases was 272. Of these, BAE group involved 63 and non-BAE group involved 209. 69 cases had the malignant pulmonary lesions, 149 cases had non-malignant chronic lung lesion such as the mycobacteria infection, fungus ball, or bronchiectasis (BE), and 54 cases had the other pathologic conditions. For each sub-groups such as 'malignant lung lesion' group, 'non-malignant chronic lung lesion' group as well as about all cases, the adjusted hazard ratios (HRs) of BAE for death was not significantly different compared to the conservative management. But the adjusted HRs as to underlying causes such as 'malignant lung lesion' group and 'the other conditions' group increased significantly compared to 'non-malignant chronic lung lesion' group. Conclusion : There was no significant survival benefit by BAE procedure on survival in patients presenting with non-traumatic hemoptysis.

• Journal of The Korean Association of Information Education
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• v.20 no.2
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• pp.139-150
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• 2016

The development of Smart devices has become a key influence on the changes of the school system. As Smart education is integrated and institutionalized in school systems, how it is perceived and utilized by teachers should be investigated. This study is conducted to find out the perception of the teachers on characteristics of Smart education, using qualitative research method, and to analyze importance-performance, using additional quantitative analysis. To figure out the perceptions of the attributes of Smart education by teachers, related literatures were reviewed. The 8 teachers were selected and the data on their perceptions of Smart education were collected through direct observation of class and semi-structured in-depth interview. After researching, we finally drew out 16 final concepts, 6 sub-categories, and 3 categories in the open coding process. Based on the 16 concepts on teachers' perceptions on Smart education, importance-performance analysis (IPA) were conducted to identify areas that need focus and improvement. Based on the results of teachers' perceptions on importance of and the levels of use of Smart education, recommendations were provided for better practice of Smart education in school.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.3
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• pp.379-395
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• 2006

The purpose of this study is to analyze the spatial characteristics of travel patterns and travel behaviors of transit users in the Metropolitan Seoul area. We apply the data mining techniques to explore the travel patterns of transit users from the T-money card database which has been produced over 10,000,000 transaction records per day. The database contains the information of locations and times of origin, transfer, and destination points for each transaction as well as the informations of transit modes taken via the transaction. We develop an data mining algorithm to explore traversal patterns from the enormous information. The algorithm determines the travel sequences of each passenger, and produce the volumes of support on each points (stops) of transportation networks in the Metropolitan Seoul area. In order to visualize the spatial patterns of travel demands for transit systems we apply GIS techniques, and attempt to investigate the spatial characteristics of travel patterns and travel demand. Subway stops located in the Gangnam area appear the highest peak for the travel origin and destination, while the CBD in the Gangbuk stands at the second position. Two or three sub-peaks appear at the densely populated residential areas developed as the high-rise apartment complex. Subway stations located along the Subway Line 2, especially from Guro to Samsung receive heavy travel demand (total support), while bus stops located at the CBD in the Gangbuk stands the highest travel demand by bus.

• International Commerce and Information Review
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• v.13 no.2
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• pp.95-117
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• 2011

The Purpose of this study is to identify important factors in choosing liner shipping companies using the AHP. The Analytic Hierarchy Process(AHP), introduced by Satty T. L. in 1970, is a decision technique the has been applied to private and public sectors and to group decision problems. This paper will demonstrate the level of importance in 4 major factors: cost, service, transportation and promotion. In detail, the 4 major factors are divided into 14 sub-factors. In the present research, various service attributes for shipping lines were selected from previous studies and the observed data for 4 main service attributes were collected through a questionnaire survey from 26 concerned international freight forwarder experts. The conclusion of this study is as follows. First, it is found that the cost factor is the most important factor among the 4 main service attributes. It is very obvious that the cost factor directly affects the choosing the liner shipping company by international freight forwarders. Second, it is found that the second important factor in choosing the liner shipping company is the transportation factor and the third is the service factor. The promotion factor is underestimated, comparatively speaking. With the ever-increasing competition, liner shipping companies will need to study and understand the selection criteria of their clients(international freight forwarder), and apply the results to their daily and long-terms operations. In particular, liner shipping companies should establish a system to identify and sort the various selection criteria used by international freight forwarding companies.

• International Commerce and Information Review
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• v.14 no.1
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• pp.301-314
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• 2012

To improve support for damages due to FTA and competitive power to overcome it, direct damages to farming and fisheries are compensated through Direct Payment Policy and Business Cessation Support System. Support plans will be developed to enhance competitive power in industries and income base in rural areas. This study carried an AHP to decide Priority and Evaluation Criteria in respect to domestic support measures according to FTA. For the AHP, the classes were categorized into direct damage conservation, higher competitive power and expansion of income. For the direct damage preservation measures, the classes were categorized into farmers, fishermen, manufactures, service business managers, and workers. In respect to reinforcement of competitive power of each industry, the classes were categorized into farming, fisheries, manufacturing, the drug industry, and service business. In respect to expansion of income, the classes were categorized into farming and fishing. Then 27 national support measures were presented for sub-classes. As a result of the analysis, it was discovered that more weight was given to measures to reinforce competitive power of each industry and expand income than those on direct damage conservation. In respect to higher competitive power in industries, more weight was given to support for farming and manufacturing. In respect to expansion of income, more weight was given on measures on farming than fisheries. For the direct damage preservation measures, more weight was given on support measures on farmers and workers.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.3
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• pp.281-288
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• 2001

Lymphangiomas are relatively rare benign tumors of the lymphatic system, characterized by congenital lymphatic malformation such as anastomosis or obstuction of the lymphatic channels. There are most frequently diagnosed in children younger than 3years. In contrast to that of the hemangioma, the sex distribution of the lymphangioma is nearly evenly divided. The head and neck lymphangioma represents about $70{\sim}75%$ of all lymphangiomas, and they are difficult to manage. Spontaneous regression is rare, and rapid intermittent enlargement occurs secondary to infection or trauma. Enlargement may cause serious sequelae such as airway obstruction, feeding difficulties, and cosmetic problems. Treatments previously used for lymphangiomas include surgical excision and intralesional injection of sclerosants. Problems associated with surgical excision include the risk of cosmetically unacceptable scarring and the risk of damage to surrounding vital stricture and the high risk of incomplete excision. The sclerosants previously used have numerous other local and systemic side effects. This report describes a case that was successfully treated using OK-432 as a new sclerosant drug and secondary surgical excision for congential cavenous lymphangioma extensively enlarged to tongue, mouth floor and submandibular region.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.3
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• pp.351-359
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• 1996

We have investigated the effect of hydrogen plasma on the formation of InAs QDs (quantum dots) structure by using a CBE (chemical beam epitaxy)system equipped with ECR (electron cyclotron resonance) plasma source. It is confirmed that the formation of self-organized InAs-QDs on GaAs is started after the growth of InAs layer up to 2.6 ML (monolayer) with the irradiation of hydrogen plasma while it is started after 1.9 ML without hydrogen gas and hydrogen plasma through the observation of RHEED patterns. Density and size of the QDs formed at $T_{sub}=370^{\circ}C$ are $1.9{\times}10^{11}cm^{-2}$ and 17.7 nm without hydrogen plasma, and $1.3{\times}10^{11}cm^{-2}$ and 19.4 nm with hydrogen plasma, respectively. It is also observed from the PL(photoluminescence) measurement on InAs-QDs that red shift in PL peak energy and broadening in FWHM (full width at half maximum)of PL peak caused by the effects of hydrogen plasma on the increment of size and its distribution. These effects of hydrogen plasma are considered as a act of atomic hydrogen which enhances the layer-growth of InAs on GaAs resulted from the relief of misfit strain between GaAs substrate and InAs.