• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.179-184
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• 2019

In many countries, such as developing countries where electricity is scarce, small wind turbines in the form of Off Grid are an effective solution to solve power supply problems. In some countries, the expansion of power systems and the decline of electricity-intensive areas have led to the use of small wind power in urban road lighting, mobile communications base stations, aquaculture and seawater desalination. With this change, the size of the small wind power industry is expected to have greater potential than large-scale wind power. In the case of small wind power generators, the generator is controlled at a variable speed, and the voltage and current generated by the generator have many harmonic components. To solve this problem, the AC to DC converter to be studied in this paper is a three-phase step-up type converter with a single switch. The inductor current is controlled in discontinuous mode, and has a characteristic of having a unit power factor by eliminating the harmonic of the input current. The proposed converter is composed of LCL filter and three phase rectification boost converter at the input stage and a single phase full bridge for grid connection. It is a control system with energy storage system(ESS) that the system stabilization can be pursued against the electric power.

• Journal of Life Science
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• v.29 no.9
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• pp.941-948
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• 2019

Colorectal cancer is a major health problem in industrialized countries. Ziyuglycoside II ($3{\beta}-3-{\alpha}$-1- arabinopyranosyloxy-19-hydroxyurs-12-en-28-oicacid), a triterpenoid saponin isolated from the roots of Sanguisorba officinalis L., possesses antioxidant, antiangiogenic, and anticancer properties. However, the therapeutic function of ziyuglycoside II in colitis-associated colorectal carcinogenesis is undefined. In the present study, the effect of ziyuglycoside II on colitis-associated colon cancer induced in mice using azoxymethane (AOM)/dextran sulfate sodium (DSS) was explored. The AOM model recapitulates many features of human colon cancer, but it lacks an inflammatory component. DSS induces colitis and promotes AOM-induced colon cancer in mice. BALB/c mice were injected with AOM and administered 2% DSS in drinking water. The mice were given ziyuglycoside II (1 or 5 mg/kg) orally three times per week, and colonic tissue was collected at 64 days. Administration of ziyuglycoside II markedly diminished the formation of colonic tumors. Western blot and immunohistological analyses showed that ziyuglycoside II noticeably decreased nuclear factor kappa-B-positive cells and levels of inflammation-related proteins, such as inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-${\alpha}$, and interleukin-6 in colon tissue. It also prompted apoptosis. Ziyuglycoside II treatment augmented cleaved forms of caspase-3, caspase-7, and poly (ADP-ribose) polymerase in colonic tissues. In conclusion, ziyuglycoside II could defend against colitis-associated tumorigenesis in mice by inhibiting inflammation and inducing apoptosis. This shows a promising chemopreventive potential for its use in colitis-associated colon cancer.

• Industry Promotion Research
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• v.4 no.1
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• pp.29-43
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• 2019

This study is to discusses the relevance of social welfare in Freud's psychoanalytic theory. The results of the study are as follows. First, psychoanalytic theory details the client's family history and personal history to help them identify the characteristics of the problem they have today. At this time, social workers actively listen to clients and try to get various information.Second, when used in psychoanalytic techniques, the resistance of the client can be interpreted and analyzed to help the client maintain friendly relationships with the client.Third, psychoanalytic theory can properly apply the client's current state of mind by understanding the potential conflicts or emotions that exist in the client's unconscious mind. Fourth, during the process of intervention, social workers need to deal well with the client's transition response. This process allows social workers to observe the effect of reducing the stimuli that can cause nervousness in clients.In conclusion, all the techniques of interpretation used in psychoanalytic theory are, after all, techniques that help social workers improve clients' insight into their problems and help clients solve their psychological problems themselves. The psychoanalytic theory is widely applied in social welfare.

• Korean Journal of Environment and Ecology
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• v.33 no.1
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• pp.116-123
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• 2019

This study focused on defining concepts such as biology push (biology-based biomimicry) and technology pull (technology problem-based biomimicry) in the multidisciplinary field of ecological imitation and analyzing the status of related research and technology at the domestic and international levels. From an ecological point of view, biomimicry is defined as ecological mimicry in which ideas obtained through classification and investigation of principles of biology and ecology are applied to the concepts of engineering and technology. We also defined the biology push as the ecological imitation based on biological characteristics starting from an ecological viewpoint and technology pull as the ecological imitation based on technical problems starting from technical needs. Although biomimicry studies often focus on the technology development by finding stable and eco-friendly source materials from biological and ecological characteristics, we wanted to emphasize the unlimited potential of research of biomimicry that can begin with an idea based on biological and ecological characteristics. This study presents the need to develop the research and technology further based on the biological and ecological viewpoints that can contribute to future sustainable development.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.339-345
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• 2021

'Gondalbi' (Ligularia stenocephala (Maxim.) Matsum. & Koidz.) is the most cultivated Gomchwi species because of higher yield and low in aromatic flavor and bitter taste, But 'Gondalbi' is susceptible to powdery mildew disease and leaf shriveling after harvest in Summer. To improve powdery mildew disease resistance and post-harvest leaf shriveling problem in 'Gondalbi', 'Handeari-gomchwi' resistant to powdery mildew disease and having higher yield potential used as a paternal trait donor. Powdery mildew disease resistance and post-harvest leaf shriveling as well as agronomic performance of a new variety, 'Greenbear' were tested under field and green house conditions in Pyungchang, Korea from 2007 to 2016. Expression of both maternal and paternal characteristics in 'Greenbear' including purple colored petiole ears, glossy leaf and paternal, petiole trichome, absent at the back of a leaf were confirmed. Plant size and flowering time of 'Greenbear' were similar to check line, 'Gommany', while leaf number per plant and yield were higher in 'Greenbear'. 'Greenbear' has thinner leaves (0.66mm) compared to 'Gommany (0.69 mm)', and hardness appeared slightly higher in 'Greenbear(25.1 kg/cm²)'. The resistance to powdery mildew disease of the 'Greenbear' variety was slightly lower than that of the 'Gommany' variety, but somewhat showed high resistance.

• Journal of Platform Technology
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• v.9 no.3
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• pp.3-17
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• 2021

Advanced persistent threat (APT) attacks are attacks aimed at a particular entity as a set of latent and persistent computer hacking processes. These APT attacks are usually carried out through various methods, including spam mail and disguised banner advertising. The same name is also used for files, since most of them are distributed via spam mail disguised as invoices, shipment documents, and purchase orders. In addition, such Infostealer attacks were the most frequently discovered malicious code in the first week of February 2021. CDR is a 'Content Disarm & Reconstruction' technology that can prevent the risk of malware infection by removing potential security threats from files and recombining them into safe files. Gartner, a global IT advisory organization, recommends CDR as a solution to attacks in the form of attachments. There is a program using CDR techniques released as open source is called 'Dangerzone'. The program supports the extension of most document files, but does not support the extension of HWP files that are widely used in Korea. In addition, Gmail blocks malicious URLs first, but it does not block malicious URLs in mail systems such as Naver and Daum, so malicious URLs can be easily distributed. Based on this problem, we developed a 'Dangerzone' program that supports the HWP extension to prevent APT attacks, and a Chrome extension that performs URL checking in Naver and Daum mail and blocking banner ads.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.1
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• pp.7-18
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• 2021

Recently, various connected industrial parks (CIPs) architectures using new technologies such as cloud computing, CPS, big data, fifth-generation mobile communication 5G, IIoT, VR-AR, and ventilation transportation AI algorithms have been proposed in Korea. Korea's small and medium-sized enterprises do not have the upper hand in technological competitiveness than overseas advanced countries such as the United States, Europe and Japan. For this reason, Korea's small and medium-sized enterprises have to invest a lot of money in technology research and development. As a latecomer, Korean SMEs need to improve their profitability in order to find sustainable growth potential. Financially, it is most efficient for small and medium-sized Korean companies to cut costs to increase their profitability. This paper made profitability improvement by reducing costs for small and medium-sized enterprises located in CIPs in Korea a major task. VJP (Vehicle Action Program) was noted as a way to reduce costs for small and medium-sized enterprises located in CIPs in Korea. The method of achieving minimum logistics costs for small businesses through the Korean CIPs payment system was analyzed. The details of the new Korean CIPs payment system were largely divided into four types: "Business", "Data", "Technique", and "Finance". Cost Benefit Analysis (CBA) was used as a performance analysis method for CIPs payment systems.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.221-230
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• 2021

The study attempts to suggest potential problem and solutions expected in the process of implementing KASS, which is currently under development to improve the domestic navigation safety system, and to summarize improvement effects of domestic navigation safety system anticipated by the implementation of KASS. Challenges expected in the process of implementing KASS exists in four aspects: emotional, technical, cost, safety aspects. When KASS is implemented and operates, various benefits can be realized. Benefits include cost savings by not using navigation safety systems during takeoff and landing; reduction of flight delays and cancellations by removing airway congestion; increase of aircraft accommodation capacity; reduction of carbon emissions; preparation for future aviation demands and improvement of air transportation safety; and reduction of flight accidents. In conclusion, it is expected to enter into an era of more intense competition due to increased aviation demands. In order to survive in this competitive environment, early introduction of KASS is indispensable. Analysis results of this study are expected to provide reference information for academic research in this area. A possible future research topic include a study predicting the changes in the navigation safety systems introduced by KASS and proposing practical and useful ways to respond the changes.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.781-792
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• 2020

Mine tailings, which are inevitably formed by the development of manganese nodules, manganese crusts, and hydrothermal seafloor deposits, have attracted attention because of their quantity and potential toxicity. However, there is a lack of data on the quantity of mine tailings being generated, their physicochemical properties, and their effects as environmental hazards and on marine ecosystems in general. The importance of treating mine tailings in an environmentally friendly manner has been recognized recently and related reduction/treatment methods are being considered. In the case of deep-sea mineral resource development, if mine tailings cannot be treated aboard a ship, the issue becomes one of the cost of transporting them to land and solving the problem of environmental pollution there. Therefore, the Korea Institute of Ocean Science and Technology conducted research on the harmfulness of mine tailings, their effect on marine ecosystem, the diffusion model of contaminated particles, and candidate purification treatment technologies based on five representative controlling factors: 1) effects of pollution /on the environment, 2) effects of environmental/ biological hazards, 3) diffusion of particles, 4) mineral dressings, and 5) reducing/processing mine tailings. The results of this study can provide a basis for minimizing environmental problems by providing scientific evidences of the environmental effects of mine tailings. In addition, it is also expected that these results could be applied to the treatment of pollutants of different origins and at land-based mining waste sites.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.439-450
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• 2020

Global warming caused by the emission of greenhouse gases into the atmosphere is being treated as a major problem for the human life, and mineral carbonation is drawing attention as one of many countermeasures against this situation. In this study, mineral carbonation experiments using autoclaved lightweight concrete (ALC) were performed under various conditions to determine its potential as a carbonation material. ALC can be regarded as a promising material for carbonation because it contains about 27 wt.% of CaO, a major component of mineral carbonation. The CaCO3 content produced as a result of the carbonation of ALC calculated on the assumption that all of the CaO content participates in mineral carbonation is about 40 wt.%. The optimum conditions for the mineral carbonation reaction from ALC are the solid-liquid ratio of 0.01 and the reaction time of 180 minutes when calcite is considered as a single product, or 0.06 and 180 minutes when mixture of calcite and vaterite can be considered. The coexistence of vaterite with calcite at solid-liquid ratio of 0.06 or higher was interpreted to be the case where vaterite formed in the later stage and did not change to calcite until the reaction was completed.