• Journal of the Korean Society for Marine Environment & Energy
• /
• v.3 no.2
• /
• pp.18-24
• /
• 2000

A two-dimensional numerical method for inviscid two-fluid flows with a significant entrainment into both directions is established, and the oil leakage from a non-pressurized underwater pipe is studied. The interface between two fluids is modeled at a vortex sheet. The flow field and the subsequent interface evolution are solved by using the vortex-in-cell method. For longer flow simulation with a realistic two fluids interaction, an efficient merging scheme is introduced. In the Boussinesq limit, the speed of the external fluid intrusion into the pipe is very close to the existing mathematical models, and the lock exchange is observed in spite of a significant roll-up of the interface and entrainments. It is believed that the developed method can be utilized effectively for further detailed studies on various two-fluid flows which are encountered in many different marine oil spill problems.

• Journal of KIISE:Computer Systems and Theory
• /
• v.34 no.1
• /
• pp.38-48
• /
• 2007

In this paper, we propose an image-based method for modeling 3D objects with curved surfaces based on the NURBS (Non-Uniform Rational B-Splines) representation. Starting from a few calibrated images, the user specifies the corresponding curves by means of an interactive user interface. Then, the 3D curves are reconstructed using stereo reconstruction. In order to fit the curves easily using the interactive user interface, NURBS curves and surfaces are employed. The proposed surface modeling techniques include surface building methods such as bilinear surfaces, ruled surfaces, generalized cylinders, and surfaces of revolution. In addition to these methods, we also propose various advanced surface modeling techniques, including skinned surfaces, swept surfaces, and boundary patches. Based on these surface modeling techniques, it is possible to build various types of 3D shape models with textured curved surfaces without much effort. Also, it is possible to reconstruct more realistic surfaces by using proposed view-dependent texture acquisition algorithm. Constructed 3D shape model with curves and curved surfaces can be exported in VRML format, making it possible to be used in different 3D graphics softwares.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.456-458
• /
• 2017

In this capstone design, weather information using Web API (Application Programming Interface) was obtained from the web and based on the information, a realistic weather displayer was made that enables users to acquire weather information more conveniently and intuitively. To implement this, weather information data according to the region is retrieved through a open API providing weather information. Based on this data, the combination of LED, submersible pump, and humidifier module realized weather effect such as rain, fog, thunder, cloudy, and sunny. You can get weather information from various regions via WiFi and get real-time weather information by retrieving data after a single weather information expression routine. In addition to Wi-Fi, we have also tested the basic performance that enables users to express the desired weather effect by enabling weather expression through Bluetooth communication.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.6
• /
• pp.1062-1068
• /
• 2007

In order to design and develop a ubiquitous game, it is necessary to develop a natural and flexible interface between the real world and the virtual world, based on social and physical context awareness. We design user interface model and the tactile sensing system that performs virtual interaction and collection of the sensor data. It is sensitive so the collected data should be filtered, rearranged and analyzed. This information is quite different from stylus input, keyboard, button or mouse for interaction. We detect kicked 3D force position of a ball, moment of area, moment of inertia and modified ball shape using tactile sensing system and analyzed data. The results demonstrate that the proposed approach is desirable and robust as well as the results can be used realistic actions and reactions considering attack force and to make interesting environments for ubiquitous game.

• Journal of the Korean Society for information Management
• /
• v.40 no.4
• /
• pp.167-200
• /
• 2023

For the record management of administrative information datasets in Korea, it is recommended to utilize SIARD as a transfer specification when transferring administrative information datasets. However, there are many cases where the application of SIARD is not suitable due to the record management unit of administrative information datasets, technical limitations of tools that support SIARD, and the realistic situation of public institutions. In this study, we propose a plan to diversify the transfer specifications of administrative information datasets other than SIARD. In the record management of administrative information datasets, the need to reproduce the user interface associated with the dataset has been discussed but not specifically presented. This study confirms that the user interface is a property to be preserved from the perspective of Significant Properties, proposes a method to effectively reproduce the user interface, and provides an example of actual verification.

• 한국HCI학회:학술대회논문집
• /
• 2008.02a
• /
• pp.573-578
• /
• 2008

Recently, we should control various devices such as TV, audio, DVD player, video player, and set-top box simultaneously to manipulate home theater system. To execute the function the user want in this situation, user should know functions and positions of the buttons in several remote controllers. Normally, people feel difficult due to these realistic problems. Besides, the number of the devices that we can control shall increase, and people will confuse more if the ubiquitous home environment is realized. Therefore, user adaptive interface that provides the summarized functions is required. Moreover there can be a lot of mobile and stationary controller devices in ubiquitous computing environment, so user interface should be adaptive in selecting the functions that user wants and in adjusting the features of UI to fit in specific controller. To implement the user and controller adaptive interface, we modeled the ubiquitous home environment and used modeled context and device information. We have used Bayesian network to get the degree of necessity in each situation. Behavior selection network uses predicted user situation and the degree of necessity, and it selects necessary functions in current situation. Selected functions are used to construct adaptive interface for each controller using presentation template. For experiments, we have implemented ubiquitous home environment and generated controller usage log in this environment. We have confirmed the BN predicted user requirements effectively as evaluating the inferred results of controller necessity based on generated scenario. Finally, comparing the adaptive home UI with the fixed one to 14 subjects, we confirmed that the generated adaptive UI was more useful for general tasks than fixed UI.

• Journal of Korea Multimedia Society
• /
• v.17 no.9
• /
• pp.1076-1083
• /
• 2014

We propose an emotional facial avatar that portrays the user's facial expressions with an emotional emphasis, while achieving visual and behavioral realism. This is achieved by unifying automatic analysis of facial expressions and animation of realistic 3D faces with details such as facial hair and hairstyles. To augment facial appearance according to the user's emotions, we use emotional templates representing typical emotions in an artistic way, which can be easily combined with the skin texture of the 3D face at runtime. Hence, our interface gives the user vision-based control over facial animation of the emotional avatar, easily changing its moods.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10b
• /
• pp.616-618
• /
• 2004

The Simple Virtual Environment (SVE) library is the application programming interface fur creating the virtual environment easily. Even though it has a lot of efficient features, applying transformation to absolutely positioned objects is difficult. In this paper, we designed a simple method with which it is possible to rotate the absolutely positioned object freely. To test the method, we designed a simple virtual environment. The environment is designed with people, street and building objects. To reduce time consumption of displaying high-detailed people models, we only used texture-based objects. The person objects are modeled as quadric-shape and textured with front-view images of people. To make more realistic environment, objects always change its orientation themselves following to the user location. The result and the testing environment will be demonstrated.

• Electronics and Telecommunications Trends
• /
• v.27 no.3
• /
• pp.62-72
• /
• 2012

IT 기술과 콘텐츠 기술이 융합된 가상현실 기술은 최근 산업, 의료, 엔터테인먼트, 교육, 문화 체험, 국방, 건축 등 적용이 널리 증가되고 있다. 본고에서는 실감형 가상현실 상호작용 기술의 동향과 활용 사례를 통하여, 핵심기술 요소와 시장 활용성 및 향후 응용 분야를 제시한다. 특히, Physical User Interface(PUI) 센서, depth 센서(혹은 RGB-D 센서) 등 3D 인터페이스를 통해 사용자의 위치 추적 및 사용자의 의도를 실시간으로 분석하고, 주변 환경에 대한 그래픽적인 표현 및 시각화에 의해 콘텐츠와 그래픽적인 표현 및 시각화에 의해 콘텐츠와 자연스럽게 상호작용하는 기법에 관한 동향을 중심으로 소개한다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.2
• /
• pp.830-842
• /
• 2015

Trust and trustworthiness of web services and organizations is calculated as scalar values. But there is still a certain level of risk for the overall reliability of this value. In this article, we focus on calculating trust values as intervals between upper and lower bounds based on predefined confidence values through an additional confidence probability. This will give us a more realistic approach to the trust assessments between individuals and organizations. We also developed a web-based software tool, TAST (Trust Assessment Software Tool) that collects the web services' evaluation of different customer groups for similar organizations through the user interface and calculates the trust intervals for predefined and previously selected confidence values. Our model uses a weighted calculation of mean and variances of customer groups in specific periods and analyses the total and incremental trust of different customer groups.