• Ocean Systems Engineering
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• 제6권4호
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• pp.363-375
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• 2016

Large numbers of submarine pipelines are laid as the world now is attaching great importance to offshore oil exploitation. Free spanning of submarine pipelines may be caused by seabed unevenness, change of topology, artificial supports, etc. By combining Iwan's wake oscillator model with the differential equation which describes the vibration behavior of free-span submarine pipelines, the pipe-fluid coupling equation is developed and solved in order to study the effect of both internal and external fluid on the vibration behavior of free-span submarine pipelines. Through generalized integral transform technique (GITT), the governing equation describing the transverse displacement is transformed into a system of second-order ordinary differential equations (ODEs) in temporal variable, eliminating the spatial variable. The MATHEMATICA built-in function NDSolve is then used to numerically solve the transformed ODE system. The good convergence of the eigenfunction expansions proved that this method is applicable for predicting the dynamic response of free-span pipelines subjected to both internal flow and external current.

• 신재생에너지
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• 제4권4호
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• pp.65-71
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• 2008

Considering the world's environmental problem, HEVs are projected as one of the solution. The keys of the HEV cruise control are expanding the use of electric motor and operating the internal combustion engine in the efficient region. This paper presents a new structure of SOC sustaining model where state-machine control is used. The proposed model defines battery charging and discharging as states and SOC of the battery as control variables. In this paper, we introduce various methods in deterministic rule-based control for HEV and describe a new SOC sustaining controller used by state-machine.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.876-882
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• 2009

With overall opening of global construction market by World Trade Organization (WTO) agreements, importance of management efficiency of construction industry which considers both tangible and intangible assets is recently being recognized in our nation. That is, efforts for reinforcement of competitiveness must be placed through maximization of values of internal and external intangible assets of construction industry such as management innovation, information, investment in technology and R&D and intellectual property. Accordingly in this study, evaluation criteria for intangible assets of construction industry were investigated and classified. Using such criteria, evaluation index and model were established based on the degree of importance of each criterion. The purpose of this study is to review importance of intangible assets in terms of competitiveness and management efficiency of construction industry and to provide basic data for establishment of intangible assets and revitalization of investment.

• International Journal of Internet, Broadcasting and Communication
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• 제15권3호
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• pp.118-121
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• 2023

Recently, green energy support policies have been announced around the world in accordance with environmental regulations, and asthe market grows rapidly, demand for batteries is also increasing. Therefore, various methodologies for battery diagnosis and recycling methods are being discussed, but current accurate life prediction of batteries has limitations due to the nonlinear form according to the internal structure or chemical change of the battery. In this paper, CS2 lithium-ion battery measurement data measured at the A. James Clark School of Engineering, University of Marylan was used to predict battery performance with high accuracy using a convolutional neural network (CNN) model among deep learning-based models. As a result, the battery performance was predicted with high accuracy. A data structure with a matrix of total data 3,931 ☓ 19 was designed as test data for the CS2 battery and checking the result values, the MAE was 0.8451, the RMSE was 1.3448, and the accuracy was 0.984, confirming excellent performance.

• 산업공학
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• 제24권2호
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• pp.128-138
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• 2011

This research proposes a resource allocation model of Data QC (Quality Control) activities using COQ (Cost of Quality). The model has been developed based on a series of research efforts such as COQ classifications, weight determination of Data QC activities, and an aggregation approach between COQ and Data QC activities. In the first stage of this research, COQ was divided into the four typical classifications (prevention costs, appraisal costs, internal failure costs and external failure costs) through the opinions from five professionals in Data QC. In the second stage, the weights of Data QC activities were elicited from the field professionals. An aggregation model between COQ and Data QC activities has been then proposed to help the practitioners make a resource allocation strategy. DEA (Data Envelopment Analysis) was utilized for locating efficient decision points. The proposed resource allocation model has been validated using the case of Korea national defense information system. This research is unique in that it applies the concept of COQ to the data management for the first time and that it demonstrates a possible contribution to a real world case for budget allocation of national defense information.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.2923-2925
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• 1999

The objective of camera calibration is to determine the internal optical characteristics of camera and 3D position and orientation of camera with respect to the real world. Calibration procedure applicable to general purpose cameras and lenses. The general method to revise the accuracy rate of calibration is using mathematical distortion of lens. The effective og calibration show big difference in proportion to distortion of camera lens. In this paper, we propose the method which calibration distortion model by using neural network. The neural network model implicity contains all the distortion model. We can predict the high accuracy of calibration method proposed in this paper. Neural network can set properly the distortion model which has difficulty to estimate exactly in general method. The performance of the proposed neural network approach is compared with the well-known Tsai's two stage method in terms of calibration errors. The results show that the proposed approach gives much more stable and acceptabke calibration error over Tsai's two stage method regardless of camera resolution and camera angle.

• Journal of Korea Trade
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• 제26권7호
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• pp.77-92
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• 2022

Purpose - This paper is an empirical investigation of the mediation effect of innovation activity in industry transformation considering the relationship between the semiconductor industry and high-quality economic development. The research questions are whether the semiconductor industry drives high-quality economic development and if so, what is the semiconductor industry's role in high-quality development? We found that the semiconductor industry has clearly improved the quality of economic development, and its comparative advantage has significantly increased per capita national incomes. Furthermore, innovation activity proved to be an intermediary factor for the semiconductor industry to promote high-quality economic development. The world economy should aim to reasonably develop the international semiconductor industry and cultivate innovation markets. Design/methodology - Our empirical model considers the relationship between the semiconductor industry, innovation activity, and high-quality economic development. We constructed an analysis framework based on data from 199 World Bank economies between 1995 and 2019, and we used a mediation effect method to calculate the total effect of the semiconductor industry on promoting high-quality economic development, the indirect effect of the semiconductor industry on promoting innovation activity, and the mediation effect of these innovation activities on the promotion of high-quality economic development. Findings - The results show that the semiconductor industry has significantly promoted high-quality economic development. This is true even after the robustness test of grouping and alternative variables was applied. An analysis of the mechanism shows that promoting patents, scientific research, efficient government, and urban management innovation are important mechanisms for the semiconductor industry to release high-quality development dividends. Originality/value - Although it has been shown that specific industries like semiconductors can affect high-quality economic development through industrial upgrading, few researchers have attempted to empirically test the impact of the semiconductor industry on high-quality economic development. In this paper, we use a mediation effect model, alternative variables and a grouping test to find the internal mechanisms of the comparative advantage of the semiconductor industry in high-quality economic development from the perspective of innovation activity.

• 한국컴퓨터정보학회논문지
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• 제26권3호
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• pp.19-28
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• 2021

위내시경 촬영은 조기에 위 병변을 진단하기 위해서 주로 사용한다. 하지만 위내시경을 했음에도 불구하고 위 내부를 자세히 관찰하지 못해서 10~20% 위 병변을 놓치는 경우가 생기는 것으로 보고되고 있다. 미국, 영국, 일본 등의 일부 국가와 세계내시경협회(Wold Endoscopy Organization)에서는 위내시경 시에 맹점 없는 관찰을 위해서 반드시 촬영해야 할 부위에 대한 촬영지침을 제안한 바 있다. 이에 본 논문에서는 수련의가 내시경을 하는 데 있어 위 내부를 자동으로 맹점 없이 관찰하는데 필요한 딥러닝 기술인 해부학적 분류모델을 제안한다. 제안한 모델은 위내시경 이미지에 적합한 전처리 모듈과 데이터 증강 기술들을 사용한다. 실험결과를 통해 최대 F1 점수 99.6% 분류 성능을 확인하였다. 또한, 실제 데이터를 통한 실험결과에서도 에러율이 4% 미만을 보였다. 이러한 성능을 바탕으로 설명 가능한 모델임을 보여 임상에서의 사용 가능성을 확인하였다.

• Journal of information and communication convergence engineering
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• 제15권4호
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• pp.217-226
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• 2017

Korea has the tenth largest film industry in the world; however, detailed analyses using the factors contributing to successful film commercialization have not been approached. Using big data, this paper analyzed both internal and external factors (including genre, release date, rating, and number of screenings) that contributed to the commercial success of Korea's top 10 ranking films in 2011-2015. The authors developed a WebCrawler to collect text data about each movie, implemented a Hadoop system for data storage, and classified the data using Map Reduce method. The results showed that the characteristic of "release date," followed closely by "rating" and "genre" were the most influential factors of success in the Korean film industry. The analysis in this study is considered groundwork for the development of software that can predict box-office performance.

• 드라이브 ㆍ 컨트롤
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• 제19권2호
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• pp.36-44
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• 2022

Hydrogen energy as an alternative source of energy has been receiving tremendous support around the world, and research is being actively conducted accordingly. However, most of the studies focus on hydrogen storage tanks and only are few studies on interpreting the hydrogen filling system itself. In this study, with reference to SAE J2601, a hydrogen fueling protocol, a simulation model was developed that can confirm the behavior of the vehicle's internal tank during hydrogen fueling. With respect to factors such as fuel supply temperature, ambient temperature, and pressure increase rate, the developed model can check the change of temperature and pressure in the tank and the state of hydrogen charging during hydrogen fueling. The validity of the developed simulation model was confirmed by comparing the simulation results with the experimental results presented in SAE J2601.