• Journal of Aerospace System Engineering
• /
• v.12 no.2
• /
• pp.23-29
• /
• 2018

Contrail is type of clouds which are formed by a condensation of water vapour from the aircraft exhaust when the aircraft is flying the cold atmosphere. Since contrails have considerable effect on greenhouse-effect and military stealth efficiency, researches about contrail avoidance technology has been conducted for decades. However, none of the previous researches concerning contrail avoidance was carried out in Korea. Thus, review of the previous study regarding contrail reduction is absolutely needed. In this paper, researches conducted by several countries are categorically introduced, and practicabilities of their methods are analyzed. This paper also suggests some practical and systematized way to conduct future researches about contrail avoidance.

• Journal of Digital Convergence
• /
• v.11 no.9
• /
• pp.349-356
• /
• 2013

The user experience of the game contents refers to the overall experience which players feel in the game play. As this experience increases, the immersion and satisfaction level extend. Therefore, the user experience is an important factor in determining success of the game. This study has the purpose for presenting importance of user experience about SNG (Social Network Game), which is the focal point recently. For this purpose, this study analyzes features of successful SNG game by comparing essential elements of user experience, such as user interface, usability, and interaction design elements. And then, this study discusses the user experience elements for enhancing the possibility of success of SNG game. This study can provide the information which is beneficial to the game immersion of SNG game players and user experience.

• Journal of Digital Convergence
• /
• v.15 no.2
• /
• pp.11-25
• /
• 2017

The primary purpose of this study is to present the fact that high-speed internet service should be designated as universal service because it becomes an indispensible and crucial service in the modern information society but free market system fails to implement universal service of high-speed internet service. To do so, it theoretically analyses previous works related to the issue of high-speed internet service and universal service in a critical point of view and investigates the current situation that high-speed internet service is not designated as universal service. In conclusion, this paper suggests that high-speed internet service should be included in the scope of universal service, in terms of infrastructure and minimum transmission speed, for the development of democracy and the information society.

• Journal of Science and Technology Studies
• /
• v.12 no.1
• /
• pp.45-78
• /
• 2012

What is a disaster? And what can science and technology studies tell us about it? There might be numerous definitions about disaster. In this article, we will posit that disaster is an incident when sociotechnical system actor-network broke down against the other force in their "trial of strength". This is a process that punctualized actor-network is depunctualized, and a status that readiness-to-hand of Being recedes while pesentness-at-hand of tool-being comes forward. Using the concept of disaster as a case study, we will consider how Latourian ontology overlaps with Heideggerian philosophy of technology. This STS approach which hasn't been previously studied might provide us with new theoretical framework that enables us to construe the assemblage of technoscience and nature-society in the field of PUS or NPSS.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.714-717
• /
• 2017

Among the factors considered in the design stage of a space launch vehicle using liquid propellant, research has been focused out on the pogo phenomenon, longitudinal dynamic instability. The pogo phenomenon refers to the instability that the longitudinal vibration of the launch vehicle structure causes a change in the pressure and flow rate of the fluids in propulsion system, and this change re-excites the fuselage structure. This mechanism constitutes a closed system to gradually increase the vibration of the launch vehicle. This paper specifically focuses on the dynamic analysis of pressure and flow changes in the propulsion system. Based on the example study of the space shuttle, the acoustic modal analysis of the propulsion system is performed to predict the modes of the supply line causing instability of the fuselage.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2007.11a
• /
• pp.1015-1018
• /
• 2007

VE is one of the most effective and systematic tool available to achieve the required function at minimum cost and manage in many industrial fields. The purpose of the preparation phase VE job plan is to establish a cooperation system referring to groups for the successful implementation of VE, and to achieve a common objective to collect sufficient materials required in the analysis phase. The Quality Model is used to measure the requirement of shareholders(users and owners)in the project. It also offers a guideline on decision making when executing the function definition, function arrangement, function evaluation, and the idea evaluation of VE. However, the current the preparation phase business confirms that the required items of owners and users has not suggested definite goals and directions. This study analyzes the problems of current work in the preparation phase from case study, survey and interviews of experts. It then proposes a new process after understanding the required items of owners, users and experts.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.10C
• /
• pp.887-901
• /
• 2002

Software management model divided into the software project model and design estimation model, software matrices model, reliability growth model, process improvement model(or process maturity model) etc. Among these software management models, software complexity model make an estimated of the product software. For a practice of software managed, need to guideline of the static analysis of software. Especially, Software complexity model introduced for the estimation of software quantity and program complexity. In case of measurement the software matrices, its need for us to analysis of software quality and products. On the other hand, we known that complexity program include many defects and consuming of source cost. So, we apply to complexity model using of the program complexity, control structure and volume matrices, interface metrics, process complexity metrics method. In this paper, we represent that the analysis of fault data detected during the system test. Also, we analysis of program control structure and interface, volume matrices in various aspect of switching software. Others, their results utilized similar of project and system development.

• Journal of KIISE:Software and Applications
• /
• v.33 no.7
• /
• pp.615-623
• /
• 2006

A non-functional requirement is a property or quality that the proposed systems have to support the functional requirements. A non-functional requirement is reflected by quality attribute These non-functional requirements playa crucial role during system development, serving as selection criteria for choosing among decisions. It should be continuously considered through the software development process. In spite of the importance of the non-functional requirements, it received little attention because of ambiguousness and invisibility of non-functional requirements. Therefore non-functional model which is a process to analyze the non-functional requirement is proposed for improving the management efficiency of non-functional requirements. Also, this paper presents the trace among the UML diagrams to the conceptual model. According to the non-functional requirement development process, this paper achieved performance-based case study. After then, non-functional requirement should be traced using the UML diagrams.

• Journal of Elementary Mathematics Education in Korea
• /
• v.21 no.4
• /
• pp.643-662
• /
• 2017

The first appearance of the equations in elementary school mathematics is in the expression of the equal sign in the addition sentences without its definition. Most elementary school students have operational understanding of the equal sign in equations. Moreover, students' opportunities to have a clear concept of the properties of operations are limited because they are used implicitly in the textbooks. Based on this fact, it has been argued that it is necessary to introduce the properties of operations explicitly in terms of specific numbers and to deal with various types of equations for understanding a relational meaning of the equal sign. In this study, we use equations to represent the implicit properties of operations and the relational meaning of the equal sign in elementary school mathematics with respect to students' level of understanding. In addition, we give some explicit examples which show how to apply them to make efficient computations.

• Proceedings of the Korea Contents Association Conference
• /
• 2008.05a
• /
• pp.431-435
• /
• 2008

Thanks to the development of internet, on-line market expands exponentially and corresponding solid business models are drawn attentions. Most of on-line trading items are limited with selling game related items however, Linden Lab made its turning point by introducing cyber reality game to shape the cyber life with creating his own Avatar in 2003. After 2003, Second life has grown sharply that over 12 million users around the world. While former games are progressed within fixed scenario, the concept of avatars who live his or her own lives at the cyber space that successfully differentiate from former online game. Further, cyber money, Linden Dollar can be used to buy real estate, cloth, shoes just like at real economy system. Not only for using corporate marketing, various areas of activities; promotion of public sector, politics, education are also functioned at the cyber life. In Korea, Korean version of Second life was introduced at the end of 2007 that draws attentions from the users. In this study, I examine various business models of cyber through Second life and suggest feasible culture-contents applying models.