• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.480-480
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• 2018

전 세계적으로 자연 친화, 하천생태계 보전, 친수하천 등을 조성하기 위한 대대적인 하천 정비사업이 활발히 진행 중에 있다. 최근 홍수로 인한 제방 붕괴에 대응하기 위한 제방의 안정화 및 개선을 위한 방법으로 기존의 시멘트와 같은 혼합물질을 사용하지 않고 환경 친화적이고 지속 가능한 대안에 대한 수요가 증가되고 있는 추세이며 현재 노후화 된 불안정 제방에 대한 보강대책을 수립해나가는 과정으로써 친환경 신소재를 활용하여 제방을 보호하는 연구가 수행되고 있다. 제방사면에 적용되는 신소재는 바이오폴리머를 활용한 재료로써 공동연구기관 카이스트에서 개발된 환경 친화적인 물질로 미생물에 의해 유도된 고인장 및 인체 무해성 등의 특성을 갖고 있으며 경제적 타당성인 측면에서 시멘트와 비교 분석 되어야 하고 실제 현장에서의 적용 가능성, 신뢰성 및 내구성 검토 등 성능을 보장하기 위한 지속적인 연구가 필요한 상황이다. 이에 본 안동하천실험센터에서는 중규모 제방을 직접 제작하여 수리모형실험을 통한 친환경 신소재 활용 제방의 안정성 및 성능 평가를 실시하였다. 수리실험 조건은 카이스트에서 제시된 레시피를 기반으로 먼저 분말형태의 바이이폴리머를 물과 희석하여 만들어진 바이오폴리머 용액을 흙과 혼합한 뒤 제방표면에 직접 미장작업을 수행하여 실험조건에 따라 일정한 두께(1cm, 3cm, 5cm)로 피복하였다. 이후 월류 붕괴 실험이 가능한 3 - 5일 정도의 양생기간을 거쳐 실험을 진행하였다. 실험결과는 다수의 고프로(GoPro) 및 비디오 카메라 등 다양한 영상장치를 이용하여 픽셀기반의 영상분석기법을 활용한 시간 흐름에 따른 제방 사면에서의 붕괴규모를 산정하여 신소재의 피복 두께에 따른 제체의 붕괴 거동 및 안정성을 평가하였으며, 또한 제방 파괴부에서의 흐름 상황 및 유속이 붕괴 발달에 미치는 영향을 분석하기 위하여 PIV 분석을 실시하였다. 이번 연구의 최종목표는 지속적인 예비실험을 수행하여 월류 및 침투, 파이핑 등 파괴 인자 별 신소재의 성능 개선 및 개발된 새로운 공법에 대한 효과 검토를 통한 최적안을 도출함으로써 향후 실규모 실험실증을 통한 신소재 시공 및 공법에 대한 현장적용 가능성 검증을 거쳐 최종적으로 신소재 제방 공법 설계 기술, 신소재 및 공법 표준안, 제방공법 안정성 평가 가이드라인 등을 제시하고자 하며, 이러한 실험데이터를 축적함으로써 실제 제방 붕괴 시 비상대처계획 수립에 필요한 기초자료로 활용이 가능할 것으로 사료된다.

• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.437-445
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• 2018

IMO (International Maritime Organization) has been strengthening the regulations of ship emission gas such as sulfur oxides (SOX), nitrogen oxides (NOX) and carbon dioxides (CO2) to protect the marine environment. Especially, ECA (Emission Control Area) has been set and operated in the USA and US. As a countermeasure against these environmental regulations, the demand for environmentally, friendly and highly efficient vessels has led to a growing interest in technology related research with respect to electric propulsion systems capable of reducing exhaust gas. Container ships were excluded from the application coverage of the electric propulsion systems for reasons of operation at economical speed. However, in the future, the need for electric propulsion system is expected to rise, because it is easy to monitor and control so that it can be an applicate to smart ship which are represented by fourth industrial revolution technology. In this study, research was carried out to design a generator and battery capacity through the load analysis of the 6,800TEU container ship to apply the electric propulsion system of the container ship. A capacity design based on the load analysis has an advantage that the generator can be operated in a high efficiency section through the load distribution control using the battery.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.3
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• pp.169-183
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• 2019

Should a startup file for a patent subject to imitation in its quest to attract venture capital(VC) investors? Considering the US pharmaceutical biotechnology industry context, this paper attempts to answer this question by investigating the relations between the number of applied patents of startups, patent imitability, and the total amount of money the startups received as their first VC funding round. Data of 157 US-based pharmaceutical biotechnology startups founded in between 1995 and 2005 are analyzed. Empirical results from this study show that the number of applied patents is positively related to the total amount of money received at the time of the first funding round, and patent imitability is negatively related to the total amount of money received as first VC funding round. Nonetheless, the interaction term between the number of applied patents of startups and patent imitability came out as positive, raising interesting questions and implications for innovation-oriented startup entrepreneurs. The current study's empirical findings suggest that, in the pharmaceutical biotechnology sector, VC investors pay attention to the quantity and quality of the patents possessed by startups when they decide the level of funding. In particular, imitability of applied patents may not be a one-sided concept related to negative features such as the weak protectability of an invention. Rather, patent imitability may be a multi-facet element which also contains positive attractiveness of the startup's invention. Furthermore, it seems that the positive side of imitability can be augmented by the number of applied patents.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.5
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• pp.195-200
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• 2021

Due to the development of video sharing platforms, the amount of video uploads is exploding. Such videos often include various types of music, among which cover songs are included. In order to protect the copyright of music, an algorithm to find the original song of the cover song is essential. However, it is not easy to find the original song because the cover song is a modification of the composition, speed and overall structure of the original song. So far, there is no known effective algorithm for searching the original song of the cover song. In this paper, we propose an algorithm for searching the original song of the cover song using the inflection points of the melody line. Inflection points represent the characteristic points of change in the melody sequence. The proposed algorithm compares the original song and the cover song using the sequence of inflection points for the representative phrase of the original song. Since the characteristics of the representative phrase are used, even if the cover song is a song made by modifying the overall composition of the song, the algorithm's search performance is excellent. Also, since the proposed algorithm uses only the features of the inflection point sequence, the memory usage is very low. The efficiency of the algorithm was verified through performance evaluation.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.239-250
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• 2021

When considering the introduction of a new technology, it is important to accurately grasp and selectively apply the technical characteristics related to the technology in order to fully utilize the advantages of the technology. In this study, the technical characteristics of high relative importance were analyzed in order to increase the efficiency of new application of blockchain technology by companies. The technical characteristics of the blockchain identified through previous research were reclassified from the perspective of the system hierarchy, and sub-factors of the technical characteristics were derived. In addition, a questionnaire survey on the relative importance of technical characteristics was conducted for internal experts and SI experts using the Analytical Hierarchy Process (AHP) technique. As a result of the analysis, respondents evaluated data protection as the most important factor in the threat of hacking related to security. In addition, it was different that the comparison results of the importance of the technical characteristics between the experts in the company and the SI experts and the priority of the technical characteristics between the expert groups by industry. It is expected that the results of this study will be usefully utilized when using blockchain technology in enterprises in line with the upcoming changes of the 4th industrial revolution. An empirical analysis of the internal and external factors required for adoption of blockchain technology by industry and the effect of technology introduction will be a meaningful study.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.537-542
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• 2022

There is a limit to the current indoor air quality (IAQ) monitoring method using fixed sensors and devices. A mobile robot for IAQ monitoring was developed by mounting IAQ monitoring sensors on a small multi-legged robot to minimize vibration and protect the sensors from vibration while robot moves. The developed mobile robot used a simple gait mechanism to enable the robot to move forward, backward, and turns only with the combination of forward and reverse rotation of the two DC motors. Due to the simple gait mechanism, not only IAQ data measurements but also gait motion control were processed using a single Arduino board. Because the mobile robot has small number of electronic components and low power consumption, a relatively low-capacity battery was mounted on the robot to reduce the weight of the battery. The weight of mobile robot is 1.4kg including links, various IAQ sensors, motors, and battery. The gait and turning speed of the mobile robot was measured at 3.75 cm/sec and 14.13 rad/sec. The maximum height where the robot leg could reach was 33 mm, but the mobile robot was able to overcome the bumps up to 24 mm.

• The Journal of the Korea Contents Association
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• v.22 no.7
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• pp.81-88
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• 2022

This study is to investigate the perception of domestic appraisers about the possibility of using artificial intelligence (AI) and related risks from the use of AI in the appraisal industry. We conducted a mobile survey of evaluators from February 10 to 18, 2022. We collected survey data from 193 respondents. Frequency analysis and multiple response analysis were performed for basic analysis. When AI is used in the appraisal industry, factor analysis was used to analyze various types of risks. Although appraisers have a positive perception of AI introduction in the appraisal industry, they considered collateral, consulting, and taxation, mainly in areas where AI is likely to be used and replaced, mainly negative effects related to job losses and job replacement. They were more aware of the alternative risks caused by AI in the field of human labor. I was very aware of responsibilities, privacy and security, and the risk of technical errors. However, fairness, transparency, and reliability risks were generally perceived as low risk issues. Existing studies have mainly studied analysis methods that apply AI to mass evaluation models, but this study focused on the use and risk of AI. Understanding industry experts' perceptions of AI utilization will help minimize potential risks when AI is introduced on a large scale.

• Korean Journal of School Psychology
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• v.18 no.2
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• pp.269-290
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• 2021

This study was conducted to examine the moderated mediation effect of self-esteem through internet overdependence on the effect of academic stress on depression and anxiety. Surveys were conducted as part of the 13th wave of the Korea Welfare Panel Study. The survey included academic stress, internet overdependence, depression and anxiety, and self-esteem scales. A total of 383 middle school students completed surveys. Data was analyzed using SPSS 21.0 and SPSS PROCESS Macro. There were three major results. First, internet overdependence partially mediation the effect of academic stress on depression and anxiety. Second, self-esteem moderated the relationship between internet overdependence and depression and anxiety. Third, self-esteem also moderated the mediating effect of academic stress on depression and anxiety through internet overdependence. These results indicate that self-esteem is a protective factor against the negative effects of internet overdependence on mental health and of academic stress on depression and anxiety in middle school students. This paper discusses the implications of these results, this study's limitations, and suggestions for future studies.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.800-808
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• 2022

The International Maritime Organization adopted the interim standards for ship maneuverability in November 1993 for preventing collision of ships at sea and for protecting the marine environment, and based on the accumulated data, in December 2002, the established standards for ship maneuverability were adopted. However, the standards adopted are those at full load, even keel, and at least 90 % of the ship speed at 85 % of the ship's maximum power. Moreover, these standards have limitations in providing information on maneuverability under actual navigational conditions. Therefore, in this study, frequency analysis AHP analysis techniques were studied by consulting navigational officers, captains, and experts, who have significant knowledge on ship maneuverability, utilization of the current standards, and the information necessary for the operation of the actual ship. The results of this study confirmed that the necessary information on maneuverability for the navigational officer operating the vessel is information about the turning circle at a small angle of 5°-10° and z-test information at maneuvering speed, not sea speed. Additionally, in relation to speed control, additional information on deceleration inertia and acceleration inertia is needed than the information on the stopping ability at sea speed and full loaded condition. The derived results are considered to be useful as basic data for preparing guidelines for ship maneuverability necessary for navigational of icers who operate ships.

• Journal of Environmental Impact Assessment
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• v.32 no.2
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• pp.61-71
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• 2023

As differences in the impact of each species on a spatial scale occur, analysis at the landscape scale is necessary to evaluate the impact of a development project. In previous studies, the Incidence Function Model (IFM) based on meta population theory was used to analyze the impact of species on the environment that changes according to urban development. However, since the model was required at least 10 occupied areas, it is difficult to use it for species that are difficult to monitor such as endangered species. Therefore, we proposed the Incidence Function Model (IFM) using species distribution model to fill the species data. In addition, we reviewed whether the developed model can be used in environmental impact assessment. As a result of the analysis, the minimum occupancy of Prionailurus bengalensis on urban development decreased to 56.5% and the possibility of survival to 28.7%. We confirmed that It rapidly decreased from the reference points of 230 and 70habitats through analysis of the meta-population capacity according to the decrease in the number of habitats. These results can be assessing the environment impact of each species on habitat loss. And it can support decision-making on the minimum number and area of habitat for species protection. This study is expected to be used as basic data for environment impact assessment on before and after development projects and mitigation measures plans, thereby increasing the effectiveness of reduction plans.