• Journal of the Korean Geotechnical Society
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• v.26 no.2
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• pp.23-32
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• 2010

This study was especially conducted to find out the characteristics of the lightweight air-mixed soil (slurry density 10 kN/$m^3$) containing silt related to water. Compression strength, permeability, and capillary height of the lightweight air-mixed soil were studied, and also to support these studies, the structure of that soil was analyzed in detail. Air bubbles of various sizes are inside the lightweight air-mixed soil, and its distribution in a location is almost constant. A numerous tiny pores are inside the air bubbles so that the lightweight air-mixed soil can be saturated with water. Porosity is also estimated through the image analysis. Peak strength of the lightweight air-mixed soil is not dependent on water, but behavior of stress-strain is affected by the water. Permeability is about $4.857{\times}10^{-6}cm/sec$, which is a little bit higher than the clay's permeability. Capillary rise occurs rapidly at the beginning of the test until the lapse of 100 minutes and then its increase rate becomes slow. The capillary rise causes the increase of the density of the lightweight air-mixed soil, and thus it is required to pay attention to this phenomenon during structure design and maintenance of the lightweight air-mixed soil.

• Journal of the Korean Geotechnical Society
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• v.24 no.5
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• pp.129-137
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• 2008

An active application of concrete track is being expected far the future constructions of Korean railroad. In comparison with the existing ballasted tract, a concrete track is very susceptible for the settlement, since its rehabilitation requires much time and cost. When a concrete track is constructed on fine-grained subgrade soil, excessive cumulative plastic settlements due to repetitive train road may occur. In this case, the settlement of the concrete track may be effectively reduced by installing a small number of small-diameter piles beneath the track. This paper presents the effect of pile installation on the reduction of cumulative plastic settlement of concrete track. A method combining experiential equation and numerical method is proposed. Using an existing experiential equation and the estimated earth pressure distribution, the cumulative plastic strain was calculated. From the results, it is verified that the effects of the pile installation is significant to effectively reduce the cumulative plastic settlement of concrete track. The reduction effects of the cumulative plastic settlement according to the pile number and pile arrangement are presented.

• Journal of the Korea Society of Computer and Information
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• v.14 no.3
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• pp.41-49
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• 2009

Flash memory has become increasingly requestion for the importance and the demand as a storage due to its low power consumption, cheap prices and large capacity medium. This research is to design a high performance flash memory structure for the substitution of a hard-disk by dynamic prefetching of aggressive spatial locality from the spatial smart buffer system. The proposed buffer system in a NAND flash memory consists of three parts, i.e., a fully associative victim buffer for temporal locality, a fully associative spatial buffer for spatial locality, and a dynamic fetching unit. We proposed new dynamic prefetching algorithm for aggressive spatial locality. That is to use the flash memory instead of the hard disk, the proposed flash system can achieve better performance gain by overcoming many drawbacks of the flash memory by the new structure and the new algorithm. According to the simulation results, compared with the smart buffer system, the average miss ratio is reduced about 26% for Mediabench applications. The average memory access times are improved about 35% for Mediabench applications, over 30% for Spec2000 applications.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.221-232
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• 2009

To purpose of the study was to analyze faculty utility of Web-Based course support system in Universities. Data were collected from log file in server computer, 5,023 faculties and 12,733 courses offered at spring semester of 2009 in the Metropolitan area S, K, D universities were analyzed. Specifically, frequency and percentile of faculties and courses using course management system were analyzed. In addition, the frequencies and percentiles of courses using sub-functions of course management system were analyzed and X2 test used to examine the difference of frequencies of faculties and courses using course system at using announcement, providing instructional material, public bulletin board and free board. Results were as follows. The 62.28% of faculties and 50.3% of courses have used Web-Based course support system. The results of Subfunction utility analysis showed the highest use as 80.4%. in providing instructional material. However, the use of announcement functions and online discussion was more or less low. Results imply that most of faculties and course are using course management system as supplementary system of off-line instruction.

• Journal of Industrial Convergence
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• v.21 no.3
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• pp.195-202
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• 2023

This study analyzes the results of a survey based on classes conducted in the field to understand the educational needs of learners, and reflects the elements necessary for SW education. In this study, various experimental elements according to learning motivation and learning achievement were constructed and designed through previous studies. As a survey applied to this study, experimental elements in three categories: Faculty Competences(FC), Learner Competences(LC), and Educational Conditions(EC) were analyzed by primary area and secondary major, respectively. As a result of analyzing CT-based SW education by area, the development of educational materials, understanding of lectures, and teaching methods showed high satisfaction, while communication with students, difficulty of lectures, and the number of students were relatively low. The results of the analysis by major were found to be more difficult and less interesting in the humanities than in the engineering field. In this study, Based on these statistical results proposes the need for non-major SW education to improve into an interesting curriculum for effective liberal arts education in the future in terms of enhancing learners' problem-solving skills.

• The Journal of the Acoustical Society of Korea
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• v.42 no.3
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• pp.243-249
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• 2023

The occurrence of cavitation on the propeller is directly linked to the naval ship's survivability, and it is necessary to design a propeller shape that delays the cavitation inception. However, the propeller cavitation can occur under various operating conditions, thus it is important to identify whether the propeller cavitation exists during operation as well as in the design phase. To this end, it is necessary to use noise or vibration signals on board to monitor the cavitation inception. In this study, a hydrophone and an accelerometer were installed on the ship hull right above the propeller to compare the performance of analyzing cavitation inception between acoustic and vibration signals. Also, a high speed camera was used to visually observe the occurrence of cavitation through an observation window. The measured results showed that the spectral shapes between acoustic and vibration signals were different, but the level increases at each frequency band and the overall level of the frequency band from 1 kHz to 10 kHz showed a similar tendency. The Detection of Envelope Modulation On Noise (DEMON) analysis also showed similar results for both acoustic and vibration signals, confirming that both hydrophones and accelerometers can be utilized in the analysis of cavitation inception.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.7
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• pp.929-943
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• 2018

Together with the increase of public housing complex, the issues of community following residential environment under contemporary society has become an important issue and the collapse of traditional community has long been emerged as an important social issue. In order to facilitate communities within the public housing complex, various discussions have been continued, and for addressing such an issue under this study, the public housing complexes n Seoul, the capital region and other major cities have been surveyed and analyzed to draw following conclusion as the design-type study to propose a model of community facilities. It displays that there is certain limitation with respect to the diversity of programs when comparing the community facility standard defined under the public housing related laws and regulations. This is attributable to the fact that it is a limitation to satisfy the level of satisfaction for residents that expect the improvement in quality of leisure life, and the facility standard that is standardized around the physical facility environment has certain limitations to enhance the level of satisfaction for residents when the demand has been on the rise with respect to quality. For this fact, the approach in consideration of diversity for the facility standard has to be made in advance. As the utility of external space for the public housing is increased, it is reasonable to consider the plan to secure environment through the architectural factors, and it has the strength in enhancing the utility of internal and external space of the community facilities.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.6
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• pp.957-966
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• 2018

Recently, the demand for remote patient monitoring based on IoT has been increased due to aging population and an increase in single-person household. A non-contact biological signal measurement system using multiple IR-UWB radars for remote patient monitoring is proposed in this paper. To reduce error signals, a multilayer Subtraction algorithm is applied because when the background subtraction algorithm was applied to the biological signal processing, errors occurred such as voltage noise and staircase phenomenon. Therefore, a multilayer background subtraction algorithm is applied to reduce error occurrence. The multilayer background subtraction algorithm extracts the signal by calculating the amount of change between the previous clutter and the current clutter. In this study, the SVD algorithm is used. We applied the improved multilayer background subtraction algorithm to biological signal measurement and computed the respiration rate through Fast Fourier Transform (FFT). To verify the proposed system using IR-UWB radars and multilayer background subtraction algorithm, the respiration rate was measured. The validity of this study was verified by obtaining a precision of 97.36% as a result of a control experiment with Neulog's attachment type breathing apparatus. The implemented algorithm improves the inconvenience of the existing contact wearable method.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.34 no.2
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• pp.59-92
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• 2023

The purpose of this study is to suggest ways to improve medical librarians' educational programs to improve domestic medical library user services. To this end, the role of medical librarians was investigated, and the education areas were itemized, and then the MLA in the US and the KMLA in Korea were compared and analyzed. As a result, the improvement points for medical librarian education programs in Korea are: First, expansion of certification programs that select various types of education programs, education areas, education contents, and specialized fields, collaboration programs with related institutions, and education programs that advocate the value of KMLA are required. Second, there is a need for various educational programs in the current educational areas, such as 'research support service' and 'education/education design/consultation'. In particular, it is necessary to provide 'consumer health information service' and 'disaster information service' for which there is no education at all. In addition, it is necessary to precede the establishment of regulations on the domestic medical librarian education curriculum for the education of various 'information services in the field related to medicine'. Third, it is necessary to provide online education contents for librarians who have difficulty participating in face-to-face education.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.3
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• pp.88-103
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• 2023

With the recent advancement of 4th Industrial Revolution technology, transportation systems are generating large amounts of mobility data related to the individual movement trajectories of vehicles and people. There are many constraints on utilizing mobility data containing personal information. Thus, in South Korea, the processing and generation of pseudonymized information and the analysis and utilization of this information have been managed in a dual manner by applying separate agencies and technologies through the revision of the Data 3 Act and the enactment of the Data Basic Act. However, this dual approach fails to securely support the entire data lifecycle and suffers from inefficiencies in terms of processing time and cost. Therefore, to compensate for the problems of the existing Expert Data Combination System and Data Safety Zone, this study proposes an Integrated Data Safety Zone Framework that integrates and unifies the process of generating, processing, analyzing, and utilizing mobility data. The integrated process for data processing was redesigned, and common requirements and core technologies were derived. The result is an architecture for a next-generation Integrated Data Safety Zone system that can manage and utilize the entire life cycle of mobility data at one stop.