• 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.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.129-138
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• 2021

This study suggests user-friendly design fiction method applying user-centered design process. Design fiction is a method that predicts futures from design perspective with critical discourses and physical representation. It has been regarded importantly in HCI and interaction design realms as aesthetical and experiential approaches, yet not firmly established. Especially, it has not been considered from user-centered perspective which considers users and related problems. Anticipatory design based on current problems which predicts futures and defines design-oriented scenario is becoming significant. Therefore, this study regards design fiction method in relation to prior design also should consider user-centered perspective, not just experimental approaches. In this regards, this study tries to apply user-centered process, specifically affordances which lead more intuitive and direct impact on users into conventional design fiction process. This study led junior students in visual communication major into design fiction process with specific topics and the Design with Intent Toolkit amongst practices of creating affordances so as to develop new design fiction process with its diverse outcomes. Throughout the process, this study aims to suggest alternative user-friendly design fiction method beyond its critical and experiential approaches.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.3
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• pp.124-133
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• 2011

The purpose of this study is to interpret the landscape characteristics of Changdeokgung's rear garden with the idea of Yijing(意境) the way to have a sense of an imaginative object. A term of Jing(境) in Yi-jing means a boundary of man's consciousness. On the boundary of consciousness for an imaginative object, there is a situation of man's emotion to be called Qingjing(情境) to meet an object, and beyond Qingjing, there is Yijing, a consciousness of the idea and the truth. The Structure of the Yijing is an analytical framework in this study. It is clarified that the idea of Yijing and landscape characteristics of changdeokgung's rear garden to analyze works of kings and related historical documents. In result, there were three kings named Injo, Sukjeong and Jeongjo who played big roles to develop the rear garden. First, Injo had built physical structure of the rear garden, the second Sukjong enjoyed Qingjing with composing the poems of Sangrimshipkyoung(上林十景), Jeongjo clearly had made a boundary of idea of Yijing broaden. It is an effective way to interpret imaginative characteristics of our traditional landscape through the concept of Yijing the useful way to understand and systemize a subject of idealistic consciousness.

• 한국노년학
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• v.37 no.2
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• pp.445-459
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• 2017

The purpose of this study is to provide a systematic review of the nonpharmacological interventions of ADL improvement for dementia published in foreign journals for the past 10 years, and to provide general information on nonpharmacological interventions and effective intervention methods to dementia expert in clinical practice. We searched published studies in the Medline Complete, PubMed Central, and Scopus databases from January 2007 to November 2016. The main keywords used "Dementia AND (ADL OR Activities of daily living) AND Nonpharmacological interventions" and total of 9 studies were selected for analysis from 974 searched articles. The level of evidence were belonged to 3 each studies in I~III level. The mostly provided nonpharmacological interventions were exercise, the study field was variety of areas including rehabilitation(occupational therapy, physical therapy), nursing, and psychology. The Barthel Index(BI) was most frequently used assessment tools to evaluate basic activities of daily living, Cognition was most dependent variables measured with the ADL. Through this study, we provided evidence for the understanding of nonpharmacological interventions of ADL improvement for dementia. In the future, based on this study, helpful intervention needed for ADL training.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.1
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• pp.65-75
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• 2011

Power Line Communication (PLC) is a system for carrying data on a conductor used for electric power transmission. Recently, PLC has received much attention due to connection efficiency and possibility of extension. It can be used for not only alternative communication, in which communication line is not sufficient, but also for communication between home appliances. Korea Electronic Power Cooperation (KEPCO) is constructing the system, which automatically collects values of power consumption of every household. Due to the randomness and complicated physical characteristics of PLC protocol (KS X4600-1), it has been believed that the current PLC is secure in the sense that it is hard that an attacker guesses or modifies the value of power consumption. However, we show that the randomness of the protocol is closely related to state of the communication line and thus anyone can easily guess the randomness by checking the state of the communication line. In order to analyze the security of PLC, we study the protocol in detail and show some vulnerability. In addition, we suggest that PLC needs more secure protocol on higher layers. We expect that the study of PLC help in designing more secure protocol as well.

• The Journal of the Acoustical Society of Korea
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• v.40 no.1
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• pp.55-63
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• 2021

In this study, a numerical methodology is proposed for evaluating valve flow noise in a pipe conveying high pressure gas, and the effects of perforated plates on reduction of such valve flow noise are quantitatively analyzed. First, high-accurate unsteady compressible Large Eddy Simulation techniques are utilized to predict flow and flow noise by a valve in a high-pressure pipe. The validity of the numerical result is confirmed by comparing the predicted wall pressure spectrum with the measured one. Next, the acoustic power of downstream-propagating acoustic waves due to the valve flow is analyzed using an acoustic power formula for acoustic waves propagating on mean flow in a pipe. Based on the analysis results, perforated plates are designed and installed downstream of the valve to suppress the valve flow noise and the acoustic power of downstream-going acoustic waves is predicted by using the same numerical procedure. The reduction by 9.5 dB is confirmed by comparing the predicted result with that of the existing system. Based on these results, the current numerical methodology is expected to be used to reduce valve flow noise in an existing system as well as in a design stage.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.1
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• pp.25-33
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• 2021

With the development of machine learning techniques, various types of data such as vibration, temperature, and flow rate can be used to detect and diagnose abnormalities in machine conditions. In particular, in the field of the state monitoring of rotating machines, the fault diagnosis of machines using vibration data has long been carried out, and the methods are also very diverse. In this study, an experiment was conducted to collect vibration data from normal and abnormal compressors by installing accelerometers directly on rotary compressors used in household air conditioners. Data segmentation was performed to solve the data shortage problem, and the main features for the fault classification model were extracted through the chi-square test after statistical and physical features were extracted from the vibration data in the time domain. The support vector machine (SVM) model was developed to classify the normal or abnormal conditions of compressors and improve the classification accuracy through the hyperparameter optimization of the SVM.

• Journal of the Korean Geotechnical Society
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• v.37 no.1
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• pp.29-41
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• 2021

Although underground works are essential to use underground spaces in urban areas efficiently, various damages caused by constructions have often occurred, making them major social problems. Since 2018, it is stipulated in the Special Act on Underground Safety Management that appropriate construction methods must be used in the design stage to prevent various damage cases. This Special Act includes establishing an area subject to underground safety impact assessment, analysis of ground and geological status, review of effects caused by changes in groundwater, review of ground safety, and establishment of measures to secure underground safety. This study area consists of various strata in order of landfill, sedimentary silt, sedimentary sand, sedimentary gravel, weathering zone, and foundation rock. Also, the slurry wall, a highly rigid underground continuous wall, was chosen as a construction method to consider high water table distribution and minimize the influence of the surroundings in this area. However, ground subsidence occurred on the road nearby in December 2019 due to the inflow of loosening soil to the construction area. Thus, several types of site investigations were conducted to suggest an appropriate analysis method and to find out loosed ground behavior and its area for the subsided site. As a result, new design soil properties were re-calculated, and the reinforcement measures were proposed through analytical verification.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.144-151
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• 2020

The number of drones used in various fields expected to 50,000 commercial drones by 2026. is to purchase business liability insurance only for commercial drones, as the scope of use of drones expands, it necessary to improve the drone insurance system, which imposes legal obligations aircraft duties. In particular, due to the diversification of aircraft characteristics of drones, an insurance system according to the degree of risk is required. To this end, a survey on the current status of drone operation in Korea, a review of documents related to drone insurance at home and abroad, collection and analysis of drone-related data, insurance systems for each transportation method, and analysis of data on overseas drone insurance products. o derive an improvement plan for the drone insurance system for drone insurance by aircraft characteristics and operation missions, and establish insurance standards by aircraft characteristics and operation missions, derive implications through required insurance surveys by sector such as users, users, and insurance companies. Detailed insurance standards were established by calculating the degree of risk according to the physical characteristics of the aircraft, and the liability for damage according to the operation mission was specified.

• Journal of the Korea Society for Simulation
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• v.30 no.1
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• pp.55-63
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• 2021

As a study on ballistic protection performance of a weapon system that is used in combat simulation, this paper aims to propose an improvement effect of the ballistic protection performance varying with incident angle of a bullet. For this, live-fire ballistic tests were performed to determine either complete penetration(CP) and partial penetration(PP) of three types of general armor plates made of uniformly rolled steel plates against a small caliber threat using 5.45 mm bullets with various speed. The major test parameter was the material of the weapon system and incident angle of the bullet with the target. Further, to quantitatively analyze the ballistic protection performance, three existing measurement methods were used for ballistic limit velocity. The test results showed that the ballistic protection performance with the incident angle of 30 degrees was 4% to 14% varying with the material of the armor plates greater than that of 0 degrees, which was approximately 1.1 times the performance improvement on average when compared to the conventional angle of incidence of the 0 degree. Those test results are expected to contribute to developing a more realistic combat simulation addressing the parameter improving the ballistic protection performance of an armor plate.