• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.3199-3218
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• 2019

Location-based services (LBSs) have become popular in recent years due to the ever-increasing usage of smart mobile devices and mobile applications through networks. Although LBS application provides great benefits to mobile users, it also raises a sever privacy concern of users due to the untrusted service providers. In the lack of privacy enhancing mechanisms, most applications of the LBS may discourage the user's acceptance of location services in general, and endanger the user's privacy in particular. Therefore, it is a great interest to discuss on the recent privacy-preserving mechanisms in LBSs. Many existing location-privacy protection-mechanisms (LPPMs) make great efforts to increase the attacker's uncertainty on the user's actual whereabouts by generating a multiple of fake-locations together with user's actual positions. In this survey, we present a study and analysis of existing LPPMs and the state-of-art privacy measures in service quality aware LBS applications. We first study the general architecture of privacy qualification system for LBSs by surveying the existing framework and outlining its main feature components. We then give an overview of the basic privacy requirements to be considered in the design and evaluation of LPPMs. Furthermore, we discuss the classification and countermeasure solutions of existing LPPMs for mitigating the current LBS privacy protection challenges. These classifications include anonymization, obfuscation, and an encryption-based technique, as well as the combination of them is called a hybrid mechanism. Finally, we discuss several open issues and research challenges based on the latest progresses for on-going LBS and location privacy research.

• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.137-147
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• 2022

In this study, for students who gave up their studies midway through college, we investigate the reasons for dropping out of college, analyze the factors that caused students to drop out, and suggest improvement measures to effectively increase the recruitment rate of enrolled students. This study explores measures to increase student enrollment in community colleges. For this purpose, it conducted a survey of students who dropped out of G College between 2018 and 2020 from June 28 to July 9, 2021. Its analysis is based on the results of 53 students who participated in the survey. First, our results suggest that programs to develop interpersonal relationships between students, faculty, and staff are necessary. Such programs will cultivate a culture of solidarity and collective identity among students, which in turn will reinforce positive experiences in college. Moreover, by developing systems to form relationships between faculty and students, colleges can have a feedback mechanism, such as an open-study program, through which they learn what the students want and need. Through this effort, colleges can help their students adjust to campuses and enhance student satisfaction in college. Second, it is necessary to develop various extracurricular programs not only for freshmen but existing students and to run hobby and leisure activity programs. To have continuous, standing extracurricular programs instead of one-time events, colleges should set up specific goals, delivery methods and strategies. Third, colleges should renovate old and outdated buildings and facilities on campus to enhance the quality of campus life. Moreover, more comprehensive improvement of facilities and a campus environment by having various convenient and leisure facilities that meet the needs and demands of students. Fourth, it is suggested to develop programs or systems that help students to more fully engage in campus lives and activities, which in turn increases confidence and self-efficacy among students. Through such programs, students can better adjust to their majors and, therefore, will be less likely to drop out of college.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.609-616
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• 2017

National Geographic Information Institute has established a plan that preoccupies UCPs (Unified Control Points) at 2~3km intervals in urban areas by considering the distance between existing UCPs by satellite images and aerial photographs in 2015. In this study, we discussed the method of selecting the locations of optimal UCPs by simulating GPS reception environment in candidate sites for UCPs using GIS. For this purpose, we selected new candidate sites for installing UCPs using satellite images and aerial photographs, and analyzed the GPS reception environment by calculating the visibility distance from buildings around UCPs using GIS skyline analysis. The number of and the arrangement of visible satellites that are capable of GPS satellite reception from the viewpoint of sky view were showed by GIS skyline analysis. Quality evaluation results of GPS observation data were compared with average PDOP calculated from hourly PDOP and TEQC in two points of Sungkyunkwan University during 8 hours. As a result of GPS reception environment using GIS, if the PDOP increases, the data acquisition rate is lowed, and the multipath error and the cycle slip are increased. Thus, this study verified that the quality of GPS observation data can be secured by constructing three-dimensional spatial information and simulating PDOP when preoccupying multiple UCPs using GIS.

• Korean Journal of Environmental Agriculture
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• v.21 no.4
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• pp.269-273
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• 2002

A 0.19 hectare stream water purification demonstration wetland was constructed and planted with cattails from April 2001 to May 2001. Some portions of its bottom surfaces adjacent to levees have a variety of slope of 1:4 $\sim$ 1:15 and two small open water areas were installed in the wetland. These make its shape closer to a natural wetlant Nitrogen removal was a major objective of the wetlant Waters of Sinyang Stream flowing into Kohung Esturiane Lake located southern coastal region of Korean Peninsula were pumped and funneled into it. Volumes and water quality of inflow and outflow were analyzed from July 2001 through December 2001. Average inflow and outflow were 120 $m^3/d$ and 112 $m^3/d$, respectively. Hydraulic retention time was about 3.1 days. Average nitrate and total nitrogen removal rate for the early stage of the wetlands were 85.8 $mg/m^2/day$, 171.4 $mg/m^2/day$ respectively. Full establishment of cattails within a few years can develope litter-soil substrates and supply available carbon sources beneficial to the denitrification of nitrate. These can lead to increases of the nitrate retention rate. Short circuiting and dead zone areas which might be occurred due to the close-to-nature layout of the wetland were not observed during the monitoring period.

• Journal of the Korean Geographical Society
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• v.31 no.2
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• pp.255-267
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• 1996

The so-called Cultural and Historical Geography, sometimes called even as the Historical and Cultural Geography, has been defined as an interdiscipline that encompasses several disciplines in Korea. Scholars with various academic background have participated in the academic activity of the Association of Korean Cultural and Historical Geographers that was organized in the late 1980s. The academic majors of these participants are cultural geography, historical geography, history of geography, urban geography rural geography, economic geography, social and economic history anthropology, landscape architecture, and so on. It was in the 1960s that articles about the Cultural and Historical Geography appeared for the first time in the major academic journals in Korea. The pioneers of publishing these articles in the 1960s continued to conduct their research, while training students majoring in the Cultural and Historical Geography in the 1970s. All of these pioneers and their students were very active in the formation of identity vrith the Cultural and Historical Geography In the 1980s. Cultural and Historical Geography in Korea took a great leap forward both in quantity and in quality. The number of articles in the journal increased substantially, and the range of research theme and methodology extended in a great deal. It was also in the late 1980s that the Association of Korean Cultural and Historical Geographers was organized in Seoul, Korea, and this association began to publish a professional journal named Cultural and Historical Geography once a year. In the 1990s, single-authored books dealing with Korean Cultural and Historcial Geography began to appear in public as textbooks or research monographs. These books are expected to speed up the spread of Cultural and Historical Geography in Korea. If it continues to grow further both in quantity and in quality as it has been, Cultural and Historical Geography in Korea will be able to stand as an independent academic field in the future. Until then, however, it cannot but avoid its mission to contribute to an integrated development of human geography in Korea. It has already gained not only its own merit in the humanistic perspective but also its own strength in its synthetic understanding.

• 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.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.5
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• pp.129-144
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• 2012

This study was conducted to understand the community characteristics of benthic macroinvertebrates according to Growth Environment at 6 Palustrine Wetlands in a rural area. As growth environment factors, size, water depth, water inlet and water outlet, land-use and water environment was analyzed. Two years' quantitative collection of benthic macroinvertebrate was carried out, and it executed community analysis and ESB index calculation and also carried out twinspan, MDS and correlation analysis. As a result, the collected benthic macroinvertebrate was 1254 individuals with 3 Phylums, 6 Classes, 14 Orders, 35 Families, 52 Genera and 61 Species. Odonata and Coenagreionidae had the highest species and individuals. Dominance Index was 0.252~0.698, Diversity Index was 1.661~2.902, Evenness Index was 0.414~0.724, and Species Richness Index was 1.990~6.224. As a result of community analysis, when correlation analysis was executed, Dominance Index had the opposite tendency with Diversity Index and Evenness Index, which had the same tendency with the previous studies. When ESB Index was calculated, Grade 2 (polluted) had the highest species with 48 species (78.7%). It is determined from the Environmental quality evaluation and saprobity evaluation result according to ESB index that there is a need to revise environmental evaluation system more specifically. As a result of MDS analysis, the subject spots A and D had the highest similarity, and the subject spot E and D had a relatively high similarity. The life environment that is the closest related with species diversity is estimated by the land-use. As for number of Individual, it seems to have the closest relation with inlet, which is to be determined as a characteristics of Palustrine Wetland. Through such investigation, this study is expected to be utilized for various types of habitats including ecological pond and to be utilized for the increase of species diversity in rural areas.

• KIEAE Journal
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• v.12 no.4
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• pp.77-82
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• 2012

This study conducted the experiment of reduction of Volatile Organic Compounds(VOCs) and Formaldehyde concentration by Native plants, Fatsia japonica and Ardisia pusilla. The two plants are advantageous in that they are highly available as they grow wild, and being easy to get. Fatsia japonica is a plant of its wide and large leaf diverged 7 or 8 parts, which is thought to have a high effect of air purification. Ardisia pusilla has a smaller leaf than Fatsia japonica, which is characterized by more leaves and beautiful. Field measurements were performed using Fatsia japonica and Ardisia pusilla which were verified as air-purifying plants in Korea. The effect of reducing the concentration of VOCs and Formaldehyde by plant studied in a full scale mock-up model. The dimensions of the two models were equal. The concentration of Benzene, Toluene, Ethylbenzene, Xylene, Stylene, Formaldehyde were monitored, since they were known as most toxic materials. The concentration of VOCs was monitored three hours after the plants were placed and three days after the plants were placed. Field measurements were performed in models where the plants were placed and were not. As a result, they had all an effect of reducing pollution. In all cases of experiment of planting and growing volume, the more planting volume, the more excellent the effect. Toluene was more effective in Fatsia japonica and Ardisia pusilla planted, Formaldehyde was more effective in Fatsia japonica planted respectively. In planting and growing and placing experiment, the placement at sunny spot was more effective than that at scattered growing. When Fatsia japonica was placed at sunny spot, the reduction effect of Formaldehyde was the most excellent, and when Ardisia pusilla was placed at sunny spot, the reduction effect of Toluene was the most effective.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.1
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• pp.89-99
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• 2020

Although microscopic analysis of tissue slides has been the basis for disease diagnosis for decades, intra- and inter-observer variabilities remain issues to be resolved. The recent introduction of digital scanners has allowed for using deep learning in the analysis of tissue images because many whole slide images (WSIs) are accessible to researchers. In the present study, we investigated the possibility of a deep learning-based, fully automated, computer-aided diagnosis system with WSIs from a stomach adenocarcinoma dataset. Three different convolutional neural network architectures were tested to determine the better architecture for tissue classifier. Each network was trained to classify small tissue patches into normal or tumor. Based on the patch-level classification, tumor probability heatmaps can be overlaid on tissue images. We observed three different tissue patterns, including clear normal, clear tumor and ambiguous cases. We suggest that longer inspection time can be assigned to ambiguous cases compared to clear normal cases, increasing the accuracy and efficiency of histopathologic diagnosis by pre-evaluating the status of the WSIs. When the classifier was tested with completely different WSI dataset, the performance was not optimal because of the different tissue preparation quality. By including a small amount of data from the new dataset for training, the performance for the new dataset was much enhanced. These results indicated that WSI dataset should include tissues prepared from many different preparation conditions to construct a generalized tissue classifier. Thus, multi-national/multi-center dataset should be built for the application of deep learning in the real world medical practice.

• KIEAE Journal
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• v.17 no.2
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• pp.45-51
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• 2017

Purpose: Housing is the most essential element for well-being in a society. The government would continuously supply decent housings to make a better living condition for people. As various housing policies have been implemented into practice, the effectiveness of policies need to be assessed and improved to rearrange the financial resources. The indicators, such as quality of life, housing supply amount and etc, could be used to estimate housing policy to provide a guidance for a new policy direction. Though various indicators are utilized to assess the policy effect, most of the items are depend upon a relativeness in aspect to assessment goal, items, time and its weighting. Therefore, it needs an absolute indicator to compare the policy effectiveness regardless of time elapse or items. In this paper, it developed the housing welfare indicator to assess the level of living condition, utilizing the Gini coefficient which is used for explanation on income distribution. Method: To suggest an inequity indicator, this paper used Gini coefficient to explain the level of living condition which is used on economics to provide the level of income distribution. Data are collected through the Korea Housing Survey by Ministry of Land, Infrastructure and Transport between 2006 and 2014. Indicators of living condition focused on the development of the estimation model using the frequency of room use. Result: Gini coefficient between 2004 and 2014 is about 1.5 score except in year 2013, and the trend of score has been decreased slowly which means the inequality gradually improved. In this result, it implies the living condition and distribution level would be improved than before.