• Journal of the Korean Geosynthetics Society
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• v.16 no.1
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• pp.53-61
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• 2017

Seabed settlement and erosion sometimes occurr when a artificial reef is installed in soft seabed. Therefore, this study carried out CBR test and water tank settlement test to investigate settlement behavior of artificial reef according to reinforcement characteristics such as reinforced types and reinforced area. Soil types of ground are sand, silt and clay deposits. Three reinforced types were prepared: unreinforced, geogrid and hybrid bamboo mat(HBM) with different reinforced area. Laboratory test results indicated that reinforced artificial reef improved bearing capacity of ground and reduced settlement as reinforced area increased. Especially, reinforced HBM provided more bearing capacity and less settlement than reinforced geogrid.

• Korean Journal of Social Welfare
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• v.53
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• pp.75-104
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• 2003

This study was performed to analyze the process and develop the pattern of school dropout in the context of the Korean educational systems. Participants were 30 adolescents experiencing dropout one more times and their age ranged from 16 to 23. A major category derived and analysed from a grounded theory method of Strauss and Corbin(1990). The qualitative analysis indicated that dropout is contradictory experiences in Korea. Because it is emancipation from various distress of school systems as well as loss of various benefit as students, Main causes of dropout were identity problems, school frustrations(failure in school achievements), environmental disadvantaged and delinquencies. Sometimes these various causes are emerged at the same time. Most important condition of context which was decided was whether dropout was voluntary and considered. After dropout from school, it was important if there were resources such as emotional and informative supports. Especially informative support was critical to adjust after dropout. Dropout experience was divided largely into 4 patterns such as type of 'searching the identity', 'being disorganized', 'escaping' and 'frustration'. In chronological analysis resulted in 4 stages including 'stage I. loss of motivation', 'stage II. escaping from school', 'stage III. trial and error', 'stage IV changing the meaning of dropout in the life.

• Journal of Digital Convergence
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• v.22 no.2
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• pp.21-28
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• 2024

This study analyzed the current status of care policies and senior citizen issues in Korea, which has entered a super-aging society, and attempted to suggest improvement measures for desirable convergence policies. The problems of the elderly in Korea have emerged as health problems, poverty problems, loss of roles, and care problems due to changes in the concept of family, values, and socioeconomic structure. In addition, poor seniors need jobs and employment policies, and healthy middle-class seniors need policy development to enable leisure activities and volunteer activities. In particular, it is necessary to establish policies to enable people to spend the rest of their lives in elderly care facilities and elderly care hospitals through community care policies. The super-aging society accounts for more than 20% of the total population among those aged 65 or older, and according to the National Statistical Office, it is expected to become a super-aging society by 2025. Elderly welfare policies must provide various programs and the needs and services of elderly care, and in the future, a super-aging society will need to secure a lot of financial resources and maintain a productive population to cover the financial resources. In other words, the human life cycle is from birth to death, and when the ratio of natural deaths of the elderly and infants born is appropriate, the society and the country can be seen as stable, vibrant, and healthy societies.

• Economic and Environmental Geology
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• v.51 no.1
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• pp.15-26
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• 2018

The spatio-temporal variations of nitrate concentrations in groundwater of Jeju Island were evaluated by an analysis of time series groundwater quality data (N = 21,568) that were collected from regional groundwater monitoring (number of wells = 4,835) for up to 20 years between 1993 and 2015. The median concentration of $NO_3-N$ is 2.5 mg/L, which is slightly higher than those reported from regional surveys in other countries. Nitrate concentrations of groundwater in wells tend to significantly vary according to different water usage (of the well), administrative districts, and topographic elevations: nitrate level is higher in low-lying agricultural and residential areas than those in high mountainous areas. The Mann-Kendall trend test and Sen's slope analysis show that nitrate concentration in mid-mountainous areas tends to increase, possibly due to the expansion of agricultural areas toward highland. On the other hand, nitrate concentrations in the Specially Designated Groundwater Quality Protection Zones show the temporally decreasing trend, which implies the efficiency of groundwater management actions in Jeju. Proper measures for sustainable groundwater quality management are suggested in this study.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.6
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• pp.29-36
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• 2016

A wireless passive sensor network is a network which, by letting separate RF sources supply energy to sensor nodes, is able to live an eternal life without batteries. Against expectations about an eternal life, however, a wireless passive sensor network still has many problems; scarcity of energy, non-simultaneity of energy reception and data transmission and inefficiency in resource allocation. In this paper, we focus on a wireless passive sensor network providing a packet service which is tolerable to packet losses but requires timely delivery of packets. Perceiving the practical constraints, we then consider a contending-type MAC scheme, rooted in framed and slotted ALOHA, for supporting many sensor nodes to deliver packets to a sink node. Next, we investigate the network-wide throughput achieved by the MAC scheme when the packets transmitted by geographically scattered sensor nodes experience path losses hence capture phenomena. Especially, we derive an exact formula of network-wide throughput in a closed form when 2 sensor nodes reside in the network. By controlling design parameters, we finally optimize the contending-type MAC scheme as to attain the maximum network-wide throughput.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.330-330
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• 2016

투명전극은 디스플레이, 터치스크린, 태양전지 등 폭넓은 분야에서 응용되고 있어 현재 각광 받는 연구 주제 중 하나이다. 특히, ITO(인듐산화물)을 이용한 투명전극은 뛰어난 효율성 때문에 가장 주목 받고 있는 전극 형태 중 하나이다. 그러나 ITO투명전극은 인듐 소재의 희소성으로 인한 자원고갈문제 및 복원력, 투명도 등에서 취약점을 지니고 있는 것으로 보고되어 있다. 이러한 ITO 투명전극의 취약점을 보완하고, 동시에 플렉서블 디스플레이(Flexible Display) 소자에 적용 가능한 대체 투명전극에 관한 연구는 현재 가장 주목할 만한 가치가 있는 연구분야로 부각되고 있다. 본 연구에서는 대체 투명전극 중 하나로 그래핀 투명전극(Graphene Transparent Electrode)을 주목했다. PEN(Polyethylene Naphthalate) 투명기판 상에 Wet-Transfer형식으로 그래핀을 전사하여 그래핀 투명전극을 구현했으며, 복원력 확인을 위해 그래핀에 2가지 (Compressive/Tensile) 압력을 가하며 구부러짐 실험(Bending Test)을 진행하며 그래핀 투명전극의 저항값을 측정했다. 일반 금속전극의 경우, 일정한 수준 이상의 압력 또는 구부러짐이 반복되는 실험의 횟수가 증가되면 원래의 복원력을 상실하며, 저항값이 상승하는 것으로 보고된바 있다. 그러나 이번 연구에서는 그래핀 투명전극을 사용해 PEN 기판 위에 투명전극을 제작한 경우, 일정한 수준의 구부러짐 반복횟수(~1,000회) 및 구부러짐 정도(~10%) 하에서 저항값이 일정하게 유지됨을 확인할 수 있었다. 별도로, 기존에 알려져 있던 순수 그래핀(Pristine Graphene)의 취약점 중 하나인 높은 저항값을 우려하여 본 연구에서는 그래핀에 도핑을 하고, 그 영향을 분석해 보았다. 그 동안 그래핀 도핑법에 대한 적지않은 연구들이 진행되었으며, 본 연구에서는 TFSA(Bis(trifluoromethanesulfonyl)amide)라는 물질을 이용한 그래핀 도핑법을 채택했다. 실험 결과, 도핑된 그래핀 투명전극은 위와 같은 수준의 그래핀 본연의 복원력을 유지하면서 저항값은 순수 그래핀 대비 약 70% 정도 낮아짐을 확인할 수 있었다. 본 연구를 통해 그래핀 투명전극이 그래핀 고유의 특성인 높은 투명도와 복원력, 도핑으로 인한 저항값 감소가능성을 확인함으로써, 그래핀 투명전극이 ITO 투명전극의 좋은 대체자가 될 수 있는 가능성을 확인할 수 있었다.

• Journal of Korea Port Economic Association
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• v.29 no.4
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• pp.175-199
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• 2013

The purpose of this paper is tthe first, diagnosing the effect of terminal operating strategy which Busan Port container operators established and executed by the strategy execution process (XPP) model, second, enhancing the competitiveness of Busan Port Container Terminal by presenting ways to improve the executive ability of strategies. In order to achieve the purpose, this study utilized XPP 6 steps diagnostic variables of Kaplan and Dr. Norton for problems of the strategy execution of Busan Port container operators and conducted the survey of 7-point scale targeting employees of Busan Port container operators for the variable measurement.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.166-182
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• 2017

The purpose of this study was to explore the difficulties experienced by career-interrupted women and recruiters in the reemployment process. Using focused group interview(FGI), the depth interviews with six women and six recruiters had been carried out. Collected data was analyzed based on the interview and focus group research method by Corbin and Strauss(2008). Finally, eight domains in career-interrupted women' experience and five in recruiters' were created from the analysis of the data. In the context of the experience there were something in common. They include the need of proper job for woman, the lack of employment system and resource, and the negative perception of women workers. As result, we suggested implications. for solving the difficulties in the reemployment process.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.271-282
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• 2014

Cloud computing technology will provide application that needs many resources and various services to customers without any restriction of time and place. So, many of companies are now adopting cloud computing technology to this business and this trend is now increasing. However, cloud technology adoption rate is low because of security, compatibility, loss of control, security, data protection, performance and uptime, to the risk of vendor lock-in Cloud computing services, and compatibility with existing systems and anxiety. Now, many people are interest on the migration of existing systems but there are many study on this issue. So, more of study on this issue should be needed. This paper will show you the method that how to adopt cloud computing to their business and also show you evolution of cloud computing for existing system.

• Journal of Wetlands Research
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• v.24 no.2
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• pp.123-141
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• 2022

Wetland also known as "Jheelon" in Hindi language is one of the most important natural resources, contributing various economic and ecological benefits. The study gave a short review of the current status of Ramsar wetlands in India. The wildlife species, conservation measures, and their significance in Indian wetlands were also explored in this review paper. As of 2022, there are 49 Ramsar sites in India covering approximately 1,09363.6 km² of land. The largest Ramsar wetland is Sundarbans, while the smallest is Chandertal. It was found that preventing wetland loss is important even though studies about wetland degradation in various nations including India, caused directly by human activities is still limited. Since Monitoring and protecting natural wetlands, supporting scientific studies on preservation and restoration of wetlands, demand on imposing regulations for limiting pollutant discharges were recommended allowing researchers, policymakers, and practitioners to better maintain wetland and its ecosystem services.