• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.259-264
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• 2006

The purpose of this study is to suggest logical foundation and points which necessarily for establishing E-commerce of Korean shipping companies' development strategy and activation plan. In order to empirical analysis, two step analyses are adopted. Firstly, this study examines the effects of the shipping company character and the shipping environment character on the usage of E-commerce in the shipping companies. Secondly, this study examines the effects of usage of E-commerce on the performance in shipping companies. In the empirical analysis, research hypotheses are being tested mainly by a structural equation model(SEM).

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.73-75
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• 2022

본 논문에서는 자율운항선박의 예측 가능한 운항 경로 상에 잠재된 비상상황을 인식하기 위하여 운항 해역의 항적 정보를 활용한 방안과 이를 기반으로 충돌 위험과 같은 비상위험을 식별하는 프레임워크를 설계하였다. 설계한 프레임워크는 크게 항적 특성 분석 모듈, 항로예측 모듈, 위험 식별 모듈로 구성된다. 항적 특성 분석 모듈에서는 자율운항선박의 운항 해역에 관한 선박들의 항적 정보를 활용하기 위하여, 대상 VTS 관제 영역 내에서 취합된 누적 선박자동식별장치(AIS) 데이터를 이용하여 선박의 항적 특성을 분석하여 데이터베이스(DB)를 생성하였다. 그리고 운항 경로 예측 모듈에서는 누적된 항적 정보와 자율운항선박의 현재 운항 정보를 기반으로 특정 시간 동안의 운항 경로를 예측하기 위한 학습 네트워크 모델을 구성하였다. 마지막으로, 위험 식별 모듈에서는 예측한 운항 경로 상에 최근접점과 최근접점 거리 정보를 이용하여 충돌 위험 가능성이 있는 충돌위험영역을 식별하였다. 설계한 프레임워크는 자율운항선박의 육상 관제소에서 원격 제어를 통해 위험상황을 인지하고 회피할 수 있는 정보를 제공할 수 있음을 실제 항적 데이터를 활용하여 그 결과를 검증하였다.

• Journal of Intelligence and Information Systems
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• v.24 no.3
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• pp.177-198
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• 2018

Recently, as economic property it has become necessary to acquire and utilize the framework for water resource measurement and performance management as the property of water resources changes to hold "public property". To date, the evaluation of water technology has been carried out by feasibility study analysis or technology assessment based on net present value (NPV) or benefit-to-cost (B/C) effect, however it is not yet systemized in terms of valuation models to objectively assess an economic value of technology-based business to receive diffusion and feedback of research outcomes. Therefore, K-water (known as a government-supported public company in Korea) company feels the necessity to establish a technology valuation framework suitable for technical characteristics of water resources fields in charge and verify an exemplified case applied to the technology. The K-water evaluation technology applied to this study, as a public interest goods, can be used as a tool to measure the value and achievement contributed to society and to manage them. Therefore, by calculating the value in which the subject technology contributed to the entire society as a public resource, we make use of it as a basis information for the advertising medium of performance on the influence effect of the benefits or the necessity of cost input, and then secure the legitimacy for large-scale R&D cost input in terms of the characteristics of public technology. Hence, K-water company, one of the public corporation in Korea which deals with public goods of 'water resources', will be able to establish a commercialization strategy for business operation and prepare for a basis for the performance calculation of input R&D cost. In this study, K-water has developed a web-based technology valuation model for public interest type water resources based on the technology evaluation system that is suitable for the characteristics of a technology in water resources fields. In particular, by utilizing the evaluation methodology of the Institute of Advanced Industrial Science and Technology (AIST) in Japan to match the expense items to the expense accounts based on the related benefit items, we proposed the so-called 'K-water's proprietary model' which involves the 'cost-benefit' approach and the FCF (Free Cash Flow), and ultimately led to build a pipeline on the K-water research performance management system and then verify the practical case of a technology related to "desalination". We analyze the embedded design logic and evaluation process of web-based valuation system that reflects characteristics of water resources technology, reference information and database(D/B)-associated logic for each model to calculate public interest-based and profit-based technology values in technology integrated management system. We review the hybrid evaluation module that reflects the quantitative index of the qualitative evaluation indices reflecting the unique characteristics of water resources and the visualized user-interface (UI) of the actual web-based evaluation, which both are appended for calculating the business value based on financial data to the existing web-based technology valuation systems in other fields. K-water's technology valuation model is evaluated by distinguishing between public-interest type and profitable-type water technology. First, evaluation modules in profit-type technology valuation model are designed based on 'profitability of technology'. For example, the technology inventory K-water holds has a number of profit-oriented technologies such as water treatment membranes. On the other hand, the public interest-type technology valuation is designed to evaluate the public-interest oriented technology such as the dam, which reflects the characteristics of public benefits and costs. In order to examine the appropriateness of the cost-benefit based public utility valuation model (i.e. K-water specific technology valuation model) presented in this study, we applied to practical cases from calculation of benefit-to-cost analysis on water resource technology with 20 years of lifetime. In future we will additionally conduct verifying the K-water public utility-based valuation model by each business model which reflects various business environmental characteristics.

• The Journal of the Acoustical Society of Korea
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• v.21 no.8
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• pp.735-743
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• 2002

In this paper, we propose three new text-independent speaker identification methods. At first, to exclude the frames not having enough features of speaker's vocal from calculation of the maximum likelihood, we propose the FS(Frame Selection) method. This approach selects the important frames by evaluating the difference between the biggest likelihood and the second in each frame, and uses only the frames in calculating the score of likelihood. Our secondly proposed, called the Hybrid, is a combined version of the FS and WMR(Weighting Model Rank). This method determines the claimed speaker using exponential function weights, instead of likelihood itself, only on the selected frames obtained from the FS method. The last proposed, called MWMR (Modified WMR), considers both original likelihood itself and its relative position, when the claimed speaker is determined. It is different from the WMR that take into account only the relative position of likelihood. Through the experiments of the speaker identification, we show that the all the proposed have higher identification rates than the ML. In addition, the Hybrid and MWMR have higher identification rate about 2% and about 3% than WMR, respectively.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.32-32
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• 2017

2012년부터 도입된 "신재생에너지 의무할당제(RPS)"로 인하여 500MW이상의 설비 용량을 갖춘 발전소의 경우 총발전량에서 일정 비율을 신재생에너지로 공급하여야 한다. 이러한 신재생에너지 중 농업부산물은 목질계 바이오매스의 한 종류로 '탄소중립(Carbon Neutral)' 연료이며 기존 화석연료와 혼소로 활용 할 수 있는 장점을 지니고 있다. 그러나 낮은 발열량, 운송 및 저장비용, 일정하지 않은 연소특성의 문제로 인하여 대부분 노지에 방치되거나 버려지고 있다. 이러한 버려지는 농업부산물을 효율적으로 활용하기 위한 방법 중 하나로 반탄화(Torrefacation) 처리가 대두되고 있다. 반탄화 처리 시, 발열량이 증대되며, 저장과 이송에서의 이점을 갖게 된다. 그러나, 반탄화는 공정 과정중 질량손실에 따른 에너지 총량의 감소한다는 단점을 가지고 있다. 이에 본 연구에서는 효율적인 반탄화공정을 위한 질량감소모델을 제시 하고자한다. 승온 속도(heating rate)를 $7.5^{\circ}C/min$, $15^{\circ}C/min$, $22.5^{\circ}C/min$의 조건에서의 열중량분석 결과를 토대로 속도모델식(Arrhenius method, Ingraham & Marrier method 등)을 적용하여, 반응속도상수를 도출하였다. 이 반응속도상수를 이용하여 질량감소 모델을 정립하였고, 이를 실험결과와 비교, 검증하였다.

• The Journal of Engineering Geology
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• v.14 no.2
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• pp.211-222
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• 2004

In this study, a probabilistic prediction model for debris flow occurrence was developed using a logistic regression analysis. The model can be applicable to metamorphic rocks and granite area. order to develop the prediction model, detailed field survey and laboratory soil tests were conducted both in the northern and the southern Gyeonggi province and in Sangju, Gyeongbuk province, Korea. The seven landslide triggering factors were selected by a logistic regression analysis as well as several basic statistical analyses. The seven factors consist of two topographic factors and five geological and geotechnical factors. The model assigns a weight value to each selected factor. The verification results reveal that the model has 90.74% of prediction accuracy. Therefore, it is possible to predict landslide occurrence in a probabilistic and quantitative manner.

• Journal of the Korea Society for Simulation
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• v.15 no.3
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• pp.49-60
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• 2006

We propose a method to use a state transition model so that the sensing object can be distinguished through classification of signal patterns sensed by a sensor array. Focusing on the design of the model that is able to distinguish the sensed object more exactly, we present an idea in which the modeling elements, 'states' and 'transitions' are defined as each same-sized angle intervals into which the angle interval $(-\frac{\pi}{2},\frac{\pi}{2})$ is divided and the angle differences between adjacent signal values on sampling signal value sequence value sequence sensed from the sensor array in the uniform time interval, respectively. In addition we show the usefulness of our model through experiments.

• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.4
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• pp.35-43
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• 2011

This study examined the structural behaviors of foam insulated concrete sandwich panels subjected to uniform pressure. Finite element models were used to simulate the detailed shear resistance of connectors and the nonlinear behaviors of concrete, foam and rebar components. The models were then validated using data from static tests performed at the University of Missouri. Both composite and non-composite action had a significant effect on the response of the foam insulated concrete sandwich panels, indicating that the simulated shear tie resistance should indeed be incorporated in numerical analyses. The modeling approach used here conveniently simulated the structural behaviors during all loading stages (elastic, yielding, ultimate and post-failure) and was compatible with the American Concrete Institute (ACI) Code and existing design practices. The results of this study will therefore provide useful guidelines for the analysis and design of foam insulated sandwich panels under both static and dynamic loadings.

• The Journal of Society for e-Business Studies
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• v.19 no.2
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• pp.53-74
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• 2014

Ubiquitous City(U-City) is spotlighted for the new paradigm to solve the problem of urbanization using ICT technology. However, due to the lower profit and the insufficient of citizen-experience service, ubiquitous service(U-Service) is perceived negatively. In this sense, a study for user-centric profitable service development is needed. This study, as a basic research for the development of U-service, is conducted to identify the factors which are affected to acceptance of the U-Service. Technology Acceptance Model is applied for the basic model of the research. The model is modified by the U-City characteristic which has user, technology, and service perspective. The proposed model is empirically tested using survey data collected from 600 citizens of 7 U-City. Structural equation modeling is employed to test the research hypotheses. The survey analysis results are able to apply for basic research of U-Service design, and provide theoretical and practical implications.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.1
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• pp.21-29
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• 2016

The wake effects behind wind turbines were investigated by using data from a Met Mast tower and the SCADA (Supervisory Control and Data Acquisition) system for a wind turbine. The results of the wake investigations and predicted values for the velocity deficit based on the eddy viscosity model were compared with the turbulence intensity from the Lange model. As a result, the velocity deficit and turbulence intensity of the wake increased as the free stream wind speed decreased. In addition, the magnitude of the velocity deficit for the center of the wake using the eddy viscosity model was overestimated while the turbulence intensity from the Lange model showed similarities with measured values.