• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.638-640
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• 2021

The network separation environment is a network security design system that separates the internal business network from the external Internet network. It separates the internal business network from the external Internet by separating it into a business network that is not connected to the network to which the Internet is connected. The network is separated, and it is a relatively secure network structure compared to Danilman in terms of security. However, there are frequent cases of infecting internal networks by using vulnerabilities in internal systems, network devices, and security devices. In this paper, we analyze the vulnerability of IT security threats in such a network isolation environment and provide technical measures for effective security monitoring.

• Journal of Species Research
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• v.12 no.spc2
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• pp.15-22
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• 2023

During a comprehensive investigation of indigenous prokaryotic species in Korea, 20 and one bacterial strains assigned to the phyla Bacillota and Verrucomicrobiota, respectively, were isolated from diverse environmental habitats, including soil, mud, tidal flat, seawater, sand, sediment, brackish water, and healthy human urine. Based on their high 16S rRNA gene sequence similarities (>98.7%) and the formation of robust phylogenetic clades with their closest related reported species, each strain was assigned to an independent and predefined bacterial species. Since there were no published or official reports regarding these 21 isolates in Korea, they - 20 species of four families in two orders of the phylum Bacillota and one species of the phylum Verrucomicrobiota - have been reported as unrecorded species in Korea. In addition, Gram staining, colony and cell morphology, basic biochemical characteristic, isolation source, and strain ID of each species are also described in the species description sections.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.227-228
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• 2023

A floating floor generally consists of mortar bed separated from the structural RC slab by a continuous resilient layer. It is known that the floating floors are a type of vibration-isolation system to improve the impact sound insulation performance. However, some researchers have demonstrated that the amplification of vibration response at a specific range of frequencies results in an increase in the impact sound level. This study carried out the forced vibration tests to obtain the frequency response function (FRF) of a floating floor compared with a bare RC slab. Test results shows that the additional peak occur in vibrational spectrum of the floating floor except natural vibration modes of the bare RC slab. This is because the relatively flexible resilient material and mass of the mortar bed offer an additional degree of freedom in the structural system. Therefore, it could be efficient for reduction of floor impact vibration and noise to control the additional mode frequency and response of floating floors.

• Geomechanics and Engineering
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• v.37 no.6
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• pp.539-554
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• 2024

This study explores development of prediction model for seismic site classification through the integration of machine learning techniques with horizontal-to-vertical spectral ratio (HVSR) methodologies. To improve model accuracy, the research employs outlier detection methods and, synthetic minority over-sampling technique (SMOTE) for data balance, and evaluates using seven machine learning models using seismic data from KiK-net. Notably, light gradient boosting method (LGBM), gradient boosting, and decision tree models exhibit improved performance when coupled with SMOTE, while Multiple linear regression (MLR) and Support vector machine (SVM) models show reduced efficacy. Outlier detection techniques significantly enhance accuracy, particularly for LGBM, gradient boosting, and voting boosting. The ensemble of LGBM with the isolation forest and SMOTE achieves the highest accuracy of 0.91, with LGBM and local outlier factor yielding the highest F1-score of 0.79. Consistently outperforming other models, LGBM proves most efficient for seismic site classification when supported by appropriate preprocessing procedures. These findings show the significance of outlier detection and data balancing for precise seismic soil classification prediction, offering insights and highlighting the potential of machine learning in optimizing site classification accuracy.

• Smart Structures and Systems
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• v.34 no.2
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• pp.73-85
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• 2024

Smart base-isolated buildings rest on flexible pads known as base isolators that minimize the effect of external disturbances along with active/semi-active actuators. The strategies used to control these active components are typically based on system models that are known a priori. Although these models describe some of the most important dynamics of the elements involved in the system, the high degree of uncertainty in the behavior of a structure under external disturbances is very difficult to characterize using a fixed model. In this work, we propose a strategy that deals with this issue: the input that controls the actuator in the base isolation system results from the compound action of a controller that relies on a model of the system that is known a priori, and a control policy that is designed based on online data-driven inferences on the behavior of the system. In this way, the control design process incorporates both the prior information about the system and the unknowns of the system, such as non-modeled parameters and nonlinear behaviors in the building. We show through simulations the performance of the proposed method in an eight-story building subjected to seismic loading.

• Management & Information Systems Review
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• v.16
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• pp.139-159
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• 2005

In many countries the demographics clearly informs us that an aging population represent a serious problem. To this extent senior citizens welfare does matter it has developed into a public debate and genuine concern. it seems that the social issues are focused on how the socity views the social welfare policies. In a modern welfare state where the emphasis lies in pursing a high standard of living and thereby high quality of life. This does not cover the very well the old people in society, but the government clearly carries an obligation to look after and care for the retired & old people in the society. This obligation the social and economic impact that an old person faces as he/she grows old. it is important ensure that their lives carries a meaning and that they as a group will not be estranged from the mainstream of society just because they are considered to be part of the aging population. The key issues that must be addressed are 1) The impact of reduced spending power from less income. a lower income stream; 2) increasing health problems and costs; 3) the natural degradation of ones physical & mental powers; 4) and thereby an isolation from the public in general. So clearly the social policy related to the old people in society should be developed with the consent of what they believe is important to them. To ensure their minimum income level that a beneficiary of an old person's pension will receive, the monthly pension should be reflected by the official price index and be adjusted accordingly. by making the job market open for the senior citizens, expending the mandatory retirement age, give companiesincentives to hire senior citizens, there maybe an opportunity to extend to the aging population the possibility to continue to participate in the society at large.

• Journal of Preventive Medicine and Public Health
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• v.53 no.4
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• pp.289-292
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• 2020

Yemen has been faced with the worst cholera epidemic of modern times, with more than 1 million suspected cases and 3000 deaths at the time of writing. This problem is largely due to the longstanding civil war between pro-government forces and the Houthi armed movement, which has severely damaged already vulnerable sanitation and healthcare facilities and systems in the country. It is further compounded by a dire lack of basic amenities, chronic malnutrition, and unfavourable weather conditions. Another contributory component may be aerial transfer by cholera-infected chironomid insects. To contain the spread of cholera in Yemen, a nation-wide armistice should be negotiated, and national and local committees must be convened to coordinate efforts on the ground. Community isolation facilities with proper sanitation, reliable disposal systems, and a clean water supply should be set up to isolate and treat sick patients. The continuity of vaccination programmes should be ensured. Public health campaigns to educate local communities about good hygiene practices and nutrition are also necessary. The One Health paradigm emphasizes a multi-sectoral and transdisciplinary understanding and approach to prevent and mitigate the threat of communicable diseases. This paradigm is highly applicable to the ongoing cholera crisis in Yemen, as it demands a holistic and whole-of-society approach at the local, regional, and national levels. The key stakeholders and warring parties in Yemen must work towards a lasting ceasefire during these trying times, especially given the extra burden from the mounting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak worldwide.

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.63-72
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• 2010

MOV(Main Oxidizer shut-off Valves) control the combustion of launch vehicle systems by the supply and the isolation of liquid oxygen to a main combustion chamber in launch vehicle systems. Moreover, the MOV should secure a constant flow rate of liquid oxygen for combustion instability in the steady operational state. Although it has been showed that a EM(Engineering Model) with a high discharge coefficient value compared with the TM(Technology Model) fills the overall performance requirements, additional design modifications in some critical parts of the EM were conducted to improve the performance. The configurations of the pressure-control body, the middle flange, and the rips of the inlet body of the EM were modified and the performance tests have been performed with test models. Consequently, the intended improvements have been verified by the performance tests.

• Research in Plant Disease
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• v.10 no.3
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• pp.194-197
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• 2004

Incidence of tobamovirus diseases was 100％ at late growth stage of green pepper on hydroponic systems in plastic house. Infection frequency of the diseases showed 34％ of Pepper mild mottle virus (PMMoV), 41.5％ of Tobacco mild green mottle virus (TMGMV), and 24.5％ of the co-infected viruses. The two viruses specifically reacted in DAS-ELISA prepared with each polyclonal antibody. A total of 77 pure tobamovirus isolates obtained from the crops was tested for pathotype determination. The isolation frequency of tobamovirus pathotype $P_{0}$ and $P_{1,2}$ was 61 ％ and 39％, respectively. All TMGMV isolates belonged to the pathotype $P_{0}$. In restriction enzyme analysis of the cDNAs synthesized with coat protein gene of PMMoV pathotype $P_{0}$ and $P_{1,2}$, the former had two TaqI sites but the later had one.one.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.3
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• pp.78-86
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• 2013

A hybrid MIMO(Multi Input Multi Output) antenna which is operating both a monopole and a IFA(Inverted F Antenna) is designed. It's applied Vlade(Vertical lade) technique to reduce antenna space, and a diagonally fed MIMO antenna is designed on the bare board for the data communication. Return losses due to variables of antenna length are simulated for the design. Antenna for the hexa-frequency band of LTE700, CDMA, GSM, DCS, PCS and WCDMA is designed and implemented. This antenna is satisfied 3:1 VSWR over the whole design band by the measurement of return loss. And average gains and efficiencies were -3.67 ~ -2.53dBi and 42.06 ~ 55.84% for LTE700/CDMA/GSM frequency band, -3.27 ~ -1.21dBi and 47.08 ~ 75.6% for DCS/PCS/WCDMA frequency band. The isolation between 2 antenna that is one of important factors for the MIMO system was measured good performance as -8.14 ~ -25.77dB over the whole service band.