• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.3
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• pp.221-243
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• 2023

The use of roadheaders has been increasing to mitigate the problems of noise and vibration during tunneling operations in urban area. Since lack of experience of roadheader for hard rock, the selection of appropriate machines and the evaluation of cutting rates have been challenging. Currently, empirical models developed overseas are commonly used to evaluate cutting rates, but their effectiveness has not been verified for domestic rocks. In this paper, a comprehensive literature review was conducted to assess the rock cutting force, cutterhead capacity, and cutting rate to select the appropriate machine and evaluate its performance. The cutterhead capacity was reviewed based on the literature results for the site. Furthermore, a new empirical model and simplified method for predicting cutting rates were proposed through data analysis in relation to operation time and rock strength, and compared with those of the conventional model from the manufacturer. The results show good agreement for high strength range upper 80 MPa of uniaxial compressive strength.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2003.11a
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• pp.693-703
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• 2003

최근 인터넷 쇼핑몰과 관련된 연구가 다양하게 이루어지고 있다. 또한 쇼핑몰 사용자의 경험적인 측면의 중요성이 제기되면서 많은 연구에서 이를 플로우란 개념으로 설명하고 있다. 본 연구는 인터넷 쇼핑몰에서의 최적 경험으로서의 플로우와 그 동안 인터넷 쇼핑몰 관련 연구에서 쇼핑몰에서의 고객 만족과 긍정적 관계에 대해 논의가 있어온, 신뢰와 만족과의 관계를 상호 독립적이 아닌 종합적 측면에서 매개성에 관한 검증을 위해 공분산 구조 분석을 통해 경쟁모델화 하여 비교함으로써 우수 모델을 도출하였다. 그 결과 인터넷 쇼핑몰에서 플로우와 신뢰는 상호 독립적인 관계를 고려한 모델 보다 동시성 차원의 매개성의 관계를 모두 고려한 포화모델이 우수한 모델로 도출되었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.327-331
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• 2018

The purpose of this study was to design a competence teaching-learning model that could help college students improve their computational thinking among core competences in SW education. A competence teaching-learning model, UDDPAAP (Unplugged-Demonstration-Decomposition-Pattern Recognition-Abstraction-Algorithm-Programming), was designed by analyzing competences of learners with no experience in software coding, by reconstructing DMM, DDD, and DPAA among the five existing SW-based teaching-learning models, and by analyzing unplugged activity and the Bebras challenge computational thinking scale carefully. The unplugged activity partially adapted to instruction for college students and some items chosen from the Bebras challenge computational thinking scale were applied to the existing teaching-learning model. To determine the effects of the study, pretest was conducted in freshmen for computational thinking and self-confidence on the basis of the experience in SW and computer information literacy education, and posttest following instruction applying the UDDPAAP teaching-learning model. The students provided with SW education based on the UDDPAAP teaching-learning model saw their computational thinking competence improved.

• Journal of the Korean Geotechnical Society
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• v.20 no.8
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• pp.77-87
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• 2004

In this paper a back-propagation neural network model is developed to estimate the preconsolidation pressure of Korean soft soils based on 176 oedometer tests and 63 piezocone test results, which were compiled from 11 sites - western and southern parts of Korea. Only 147 data were used for the training of the neural network and 29 data, which were not used during the training phase, were used for the verification of trained network. Empirical and theoretical models were compared with the developed neural network model. A simple 4-4-9-1 multi-layered neural network has been developed. The cone tip resistance $q_T$ penetration pore pressure $u_2$, total overburden pressure $\sigma_{vo}$ and effective overburden pressure $\sigma'_{vo}$ were selected as input variables. The developed neural network model was validated by comparing the prediction results of the proposed neural network model for the new data which were not used for the training of the model with the measured preconsolidation pressures. It can also predict more precise and reliable preconsolidation pressures than the analytical and empirical model. Furthermore, it can be carefully concluded that neural network model can be used as a generalized model for prediction of preconsolidation pressure throughout Korea since developed model shows good performance for the new data which were not used in both training and testing data.

• Journal of the Korean GEO-environmental Society
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• v.13 no.3
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• pp.39-51
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• 2012

The time-dependent characteristics of mudstone in this study were analyzed by performing creep tests for the mudstone in Pohang. The creep tests were conducted on various boundary conditions to observe the time-dependent behavior of mudstone and the results were compared with values predicted by established visco-elastic model and empirical equations. As a result of analysis for empirical equations proposed by Griggs(1936), Cottrell(1952) and Singh(1975), the creep constants generally tend to increase as increasing the stress level and water content. Moreover, the values predicted by Singh's equation were well fitted for the test results. Therefore, it is expected to be reasonable that creep behavior of mudstone is analyzed using Singh's equation. As a result of analysis for a Burger's model, the predicted values were well fitted for the test results. Therefore, it is expected be reasonable that the creep behavior of mudstone by a rheological model is analyzed using Burger's model.

• Spatial Information Research
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• v.21 no.6
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• pp.11-21
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• 2013

This study aims to establish a strategic NSDI (National Spatial Data Infrastructure) model for developing countries based on good practices in the Republic of Korea. The Republic of Korea is a unique country in the world, which has become a developed country from a recipient of international aid since the Korean War in 1950. The rapid economic growth can be mostly attributed to the IT technologies and the Republic of Korea's NSDI efforts as a good practice could provide useful lessons for developing countries. This study consists of theoretical reviews, interviews of Korean NSDI experts, analysis for lessons learned, a summary of the lessons in terms of Six NSDI components and finally a strategic NSDI model for developing countries. The NSDI model is structured by (1) implementation strategies suggested for geospatial data, capacity building, geospatial platform, and cost-effective management with partnership, (2) a roadmap of important NSDI tasks and activities, and finally, (3) a harmonized approach for successful NSDI implementation.

• Journal of the Korea Society for Simulation
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• v.18 no.1
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• pp.53-62
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• 2009

The real data obtained from field exercises has a crucial role in modeling and simulation of a combat or a wargame. This becomes an important input especially in analyzing weapon systems realization. Many existing models have been using the mean value of the time between each fire. The firing data can be incorporated into a known probability distribution or used directly as an empirical distribution. Data of field exercises are very useful instead of the real combat outcomes. This study finds a new modeling approach and techniques to compare the data with the previously generated outcomes. This fundamental research work will continue to consider more of the various weapon systems, the sizes, and other tactical aspects.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.24-29
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• 2008

기술의 발달로 인하여 제품의 특징과 편익이 제품을 선택하는데 있어서의 중요성이 약화되었다. 이로 인하여 제품의 기능성을 바탕으로 하여, 사용성 더 나아가 제품을 사용하는데 있어서의 즐거움을 제공하는 것이 기업의 성공에 큰 영향을 끼치게 되었다. 이러한 제품의 기능성, 사용성, 사용하는데 있어서의 즐거움 같은 요소들이 통합되어 제품을 사용하는데 있어서의 사용자의 경험을 이루게 된다. 이러한 경험을 실제 디자인과 연관 짓는데 있어서 경험이라는 것 자체가 정성적이고 복잡한 구조를 가지고 있고, 추상적이어서 진정한 의미의 경험디자인의 단계에 이르지 못하고 있다. 본 연구에서는 무수한 요소와 여러 환경 적인 영향을 받는 복잡한 사용자 경험에 대하여, 여러 방면에서 연구되고 있는 사용자 경험의 요소들을 종합하여 그 구조 규명하였다. 또한 사용자 경험의 요소와 그 경험을 가능하게 해주는 제품의 디자인 팩터들을 정의하여, 이러한 요소들이 어떤 관계성을 갖고 어떠한 요소에 의해 영향을 받는지에 대하여 모델링 하였다.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1996.10a
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• pp.34-37
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• 1996

해상풍에 의한 파랑의 발달을 다룬 모델은 1940년대 이후 실측파랑 및 기상자료로부터 이론에 기초한 경험식이 제시되었다. 이러한 경험식들은 실제의 불규칙한 해면상태를 유의파로 대표하여 유의파의 파고 및 주기를 풍속, 취송거리 및 취송시간의 함수로 나타낸 것이다. 널리 쓰이고 있는 심해에서의 모델은 SMB법과 Wilson법이 있으며 일정한 바람이 연속적으로 불어오는 안정된 정상상태에서는 SMB법이, 그리고 풍역이 시간적 공간적으로 변화가 큰 경우에는 Wilson법이 적용되고 있다. (중략)

• Journal of Service Research and Studies
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• v.11 no.2
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• pp.67-77
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• 2021

This study is a study on the methodology of establishing an innovation strategy centering on the customer experience, which is essential in order to transform the existing collection and preservation-centered mutual aid company service into a visitor-centered service. To this end, we conducted literature research on environmental changes in the funeral industry from the perspective of service science and the significance and value of customer experiences within them, good customer experiences and bad customer experiences from the perspective of customer experience management. A study was conducted to present and prove a specific model. The customer experience-oriented innovation strategy of the funeral industry means to search for various alternatives that can reach the target state from the present state, focusing on the customer, and select the most appropriate transformation plan among them. As an effect of application, it was found that it is a source of differentiation by generating positive emotions to customers, and that customer experience data is highly helpful in making important decisions for the actual resource input of the parent company. This innovation model was presented, and its value was firstly proved by analyzing the difference from the existing evaluation method. Finally, as a result of analyzing the causal relationship through regression analysis using the customer experience measurement procedure, customer experience diagnosis/evaluation, customer experience innovation strategy, and cooperative company's performance as variables, the relationship proved to be significant.