• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.772-779
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• 2019

The subsea pipeline has received considerable attention as a high-value-added industry linked to the energy and steel industries including natural resource development. The design and installation of the subsea pipeline require a variety of key technologies to carry out the project. In particular, a thorough pre-verification process through pre-commissioning is essential for the safe operation of the subsea pipeline. The hydrotesting stage in the pre-commissioning process of the subsea pipeline is known to be affected significantly by the ambient temperature change; however, there is a little study based on the theoretical and numerical approach. In this study, the method of predicting the internal temperature change using the transient heat transfer method for the stage of hydrotesting during the pre-commissioning process of the subsea pipeline and the prediction method of the pressure variation in the pipeline using it were proposed. The predicted results were compared with field test results and its effectiveness was verified. The proposed analysis procedure is expected to contribute to the productivity improvement of the subsea pipeline installation project by enabling the prediction of pressure variation through pipeline heat transfer simulation from the initial design stage of the subsea pipeline installation project.

• The Journal of Society for e-Business Studies
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• v.13 no.4
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• pp.111-124
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• 2008

The development in information technology allowed most of the information around us into digital information, in other words, a database. The innovation increased the accessibility and helped this society change into an informational age. However, there is a shortcoming of this open source as the users have difficulty in assorting the information that s/he needs and realizing if the information provided is important. Therefore, the need for search engine has risen in such a way to increase the accessibility and facilitation of information provided to the users through searching the necessary information in the database by an easy and accurate way. This aim of study should propose the important design attribute to increase the utilization of search engine through relationship analysis between purpose of user and interface design factors of search engine. In other words, these attributes, as design guideline, could apply to the search engine interface design considering of user's search goal. For this, the purpose in using the search engine and types of search engine interfaces were categorized and correlated the relationships. The search engine interface suggested from the result provides interface that allows efficient search for desired information and embrace a variety in users, eventually increasing the usability in search engine.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.1
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• pp.85-97
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• 2003

This study was aimed at suggest a proper logging method of mountain forest using geographic information system(GIS) based on digital terrain model(DTM) in the National Forest at Mt. Kumsan in Namhae-gun, Gyungsangnam-do, which has about 2,948 ha in area. The areal percentage of 201 to 250m in the elevation was about 15.5%, elevation of 251 to 300m was 14.5%, and 78.75% for higher than 400m. The accumulated areal percentage of below 30% in the gradient was 17.2%, and 81.0% for steeper than 60%. The area for tractor skidding was 17.2%(511.7ha), the area for tractor attached winch skidding was 63.8%(1,896.3ha) and 18.4%(545.5ha) for cable yarding. It is important to choose the proper logging machines for timber harvesting. In general, the selection of logging operation system was affected several major environmental factors like as terrain conditions(slope gradient, slope length) and stand factors. The rate of middle slope gradients in terrain conditions showed higher than that of steep slope gradients in this area. Therefore, it considered that the logging operation system in this area could apply to tractor+winch operating machine according to terrain conditions.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.4
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• pp.271-277
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• 2020

There are increasing cases of monitoring the structural response of structures using multiple sensors. However, owing to cost and management problems, limited sensors are installed in the structure. Thus, few structural responses are collected, which hinders analyzing the behavior of the structure. Therefore, a technique to predict responses at a location where sensors are not installed to a reliable level using limited sensors is necessary. In this study, a numerical study is conducted to predict the seismic response of low-rise buildings using limited information. It is assumed that the available response information is only the acceleration responses of the first and top floors. Using both information, the first natural frequency of the structure can be obtained. The acceleration information on the first floor is used as the ground motion information. To minimize the error on the acceleration history response of the top floor and the first natural frequency error of the target structure, the method for predicting the mass and stiffness information of a structure using the genetic algorithm is presented. However, the constraints are not considered. To determine the range of design variables that mean the search space, the parameter prediction method based on artificial neural networks is proposed. To verify the proposed method, a five-story structure is used as an example.

• Journal of the HCI Society of Korea
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• v.13 no.2
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• pp.31-44
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• 2018

In the IoT environment, various things could be connected. Those connected things learn and operate themselves, by acquiring data. As human being, they have self-learning and self-operating systems. In the field of IoT study, therefore, the key issue is to design communication system connecting both of the two different types of subjects, human being(user) and the things. With the advent of the IoT environment, much research has been done in the field of UI design. It can be seen that research has been conducted to take complex factors into account through keywords such as multi-modality and interusability. However, the existing UI design method has limitations in structuring or testing interaction between things and users of IoT environment. Therefore, this paper suggests a new UI prototyping method. In this paper, the major analysis and studies are as follows: (1) defined what is the behavior process of the things (2) analyzed the existing IoT product (3) built a new framework driving personality types (4) extracted three representative personality models (5) applied the three models to the smart home service and tested UI prototyping. It is meaningful with that this study can confirm user experience (UX) about IoT service in a more comprehensive way. Moreover, the concept of the personality of things will be utilized as a tool for establishing the identity of artificial intelligence (AI) services in the future.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.209-220
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• 2004

The main feature of H.264 standard against conventional video standards is the high coding efficiency and the network friendliness. In spite of these outstanding features, it is not easy to implement H.264 codec as a real-time system due to its high requirement of memory bandwidth and intensive computation. Although the variable block size motion compensation using multiple reference frames is one of the key coding tools to bring about its main performance gain, it demands substantial computational complexity due to SAD (Sum of Absolute Difference) calculation among all possible combinations of coding modes to find the best motion vector. For speedup of motion estimation process, therefore, this paper proposes fast algorithms for both integer-pel and fractional-pel motion search. Since many conventional fast integer-pel motion estimation algorithms are not suitable for H.264 having variable motion block sizes, we propose the motion field adaptive search using the hierarchical block structure based on the diamond search applicable to variable motion block sizes. Besides, we also propose fast fractional-pel motion search using small diamond search centered by predictive motion vector based on statistical characteristic of motion vector.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.304-309
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• 2008

The development in information technology allowed most of the information around us into digital information, in other words, a database. The innovation increased the accessibility and helped this society change into an informational age. However, there is a shortcoming of this open source as the users have difficulty in assorting the information that s/he needs and realizing if the information provided is important. Therefore, the need for search engine has risen in such a way to increase the accessibility and facilitation of information provided to the users through searching the necessary information in the database by an easy and accurate way. This study aims to increase the utilization of search engine through relationship analysis between purpose of user and interface design factors of search engine. Also, it intends to propose design guidelines for search engine interface design in order to increase user satisfaction and usability. This study categorized and correlated the relationships of the purpose in using the search engine and types of search engine interfaces. This study explicates the critical properties in designing each search engine interface according to the purpose of the users in using them. Also, this study proposes recommendations for appropriate design guidelines for search engine interface and effective advertisement use through properties of interface and their importance. The search engine interface suggested from the result provides interface that allows efficient search for desired information and embrace a variety in users, eventually increasing the usability in search engine.

• Spatial Information Research
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• v.23 no.3
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• pp.35-44
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• 2015

Recently, the government aims to discover and provide services to citizens on the development strategy for activating the U-City. So, this study aims to offer a service discovery direction by analyzing the service issues and trends. The target is newspaper article about U-City Service from 2009 to 2014. Prepared 723 newspaper article for analysis. Next step is frequency analysis of keyword and used that result for Network analysis and measure of information. Network analysis can show result through "Degree Centrality", "Betweenness Centrality" and "Closeness Centrality". As a result, "Information", "IT", "Environment", "Technology", "Center" is higher than another. These 5 keywords are important factors for driving the U-City the past six years. Information measurement results, Already U-City were put an emphasis on building the infrastructure and able to identify a trend that provided the center of the public service. Those Service field are "Tour(2009)", "Crime prevention and Disaster Prevention(2010)", "Facility Management(2011)", "administration(2012)" and "Facility Management(2013, 2014)". Result of this study found implications what on citizen participation. So, services field on the existing infrastructure should be discovered and provided. Finally, this study can expected to be a reference in the local government planning for U-City.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.402-410
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• 2017

The effect of the steel pipe member joint on the design performance of a plastic multi-span greenhouse was analysed through the comparing full-scale experiment and numerical analysis. The design performance of the greenhouse is generally evaluated through numerical analysis, but it is rare to consider the characteristics of the connections or joints of the members. In this study, the effect of the column-gutter beam-rafter-wind break wall joint on the design performance of the whole structure of a plastic multi-span greenhouse was analysed. The numerical results with assuming that the member joint are rigid condition were compared with the full-scale load test results using member joints used in the field. The stiffness of the entire structure was compared using the load-displacement relationship and the change of the load sharing ratio that the main members such as column, rafters, and wind break wall was analysed. The results of the load test were about 40% larger than the numerical result and the member stress was more than twice as large as those of the loaded columns. In order to increase the reliability of the design performance of the greenhouse, it is necessary to develop a numerical analysis model which can consider the characteristics of various joints.

• Journal of Broadcast Engineering
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• v.25 no.3
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• pp.346-352
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• 2020

Versatile Video Coding (VVC), a next-generation video coding standard that is in the final stage of standardization, has adopted various techniques to achieve more than twice the compression performance of HEVC (High-Efficiency Video Coding). VVC adopted Bi-prediction with CU-level Weight (BCW), which generates the final prediction signal with the weighted combination of bi-predictions with various weights, to enhance the performance of the bi-predictive inter prediction. The syntax element of the BCW index is adaptively coded according to the value of NoBackwardPredFlag which indicates if there is no future picture in the display order among the reference pictures. Such syntax structure for signaling the BCW index could violate the flexibility of video codec and cause the dependency issue at the stage of bitstream parsing. To address these issues, this paper proposes an efficient BCW weight signaling method which enables all weights and parsing without any condition check. The performance of the proposed method was evaluated with various weight searching methods in the encoder. The experimental results show that the proposed method gives negligible BD-rate losses and minor gains for 3 weights searching and 5 weights searching, respectively, while resolving the issues.