• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.6
• /
• pp.38-45
• /
• 2010

Welding structures are designed to endure its expected life. The most important factors are life. Especially on welded structure, fatigue strength is critical. So this study performed a research on Box and T shape weldment specimen to examine the influence of welding type. In this experiment, the results indicate Box shape was available in more than T shape. Fatigue tests were performed to evaluate the fatigue strength of the both as-welded and statically pre-loaded specimens by 3 point bending load. Fatigue life can be improved by using Ultrasonic Impact Treatment(UIT) effect. Ultrasonic Impact Treatment(UIT) is excellent for eliminating the tensile residual stresses and generating compressive residual stresses which elevate fatigue strength of welded structures. Also, this shows that welding part has better fatigue life and welding was performed well. In this study, to evaluate the Ultrasonic Impact Treatment(UIT) effect, for welding structure, the experiment was conducted at various levels of stress range between 100MPa and 500MPa. From the test results, it was indicated that fatigue performance was improving by Ultrasonic Impact Treatment(UIT)

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.6
• /
• pp.1047-1053
• /
• 2007

As the acceleration of digital convergence has been deepen and extended to convergence of human, things, and space, the various forms of convergence have been appeared and extended. This paper presents the aim of the system's change which embodies the collaborative electronic government of the application service, which applies the UIT as the changed feature from e-Gov to u-Gov and attains the administrative idea which the u-Gov pursues. It analyzes and applies the propulsive plan of the policies to u-Gov, which is resulted from the variation of the convergence community, and the feature of the UIT, and then it proposed the service model of the new u-Gov with circulation instance adumbration which applies the UIT as the objective realization means of the ultimate administration.

• The Journal of the Korea Contents Association
• /
• v.9 no.6
• /
• pp.325-335
• /
• 2009

The effects of the U-Police Service is expected to go much beyond present police service. Scientific police service using the UIT will enable the police to confront rapidly to the crimes which has been in the blind spot of law enforcement in the result of insufficient police forces and maintenance of law and order by putting police manpower first. Cetizens' feeling of safety from crimes is also expected to be much improved and this will bring about noticeabe effect on crime prevention by suppressing the crime impulse in advance. This thesis have come up with various research results by interviewing police officers and citizen of the City of Seoul under the circumstances that there has been no positive and analytical studies on the areas that the UIT could apply to or the possibility of utilizing the UIT. As we apply the UIT to the police service, how we solve the problem occurring by adopting the UIT and how much we can protect private information is much more important than what kind of service we can provide. Especially, embodiment of U-Police service is a necessary precondition for constructing ubiquitous city in near future. Following studies to draw relevant research results by expanding the objects of the study are much needed including the study on the measurement of efficiency of U-Police service in each service sectors which the UIT applies to.

• Journal of Energy Engineering
• /
• v.24 no.4
• /
• pp.117-123
• /
• 2015

Recetly, Many industry have used unknown composition gases and no information gases. These gases were used increasing. As use increases, The more important software that can predict dispersion region and speed. It is very difficult to predict the dispersion of new gases. Because, it is predict from existing database. In this study, we propose to esimate dispersion region and speed of some gases, using a FLACS software and equivalent gas.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2003.04a
• /
• pp.377-382
• /
• 2003

본 연구는 최근 정보산업분야에서 부각되고 있는 “유비쿼터스 정보기술(UIT)”을 도시계획 정보시스템(UPIS)에 활용하기 위한 연구이다. 유비쿼터스 기술이 무엇인지, 도시계획정보시스템에서 어떠한 이점을 줄 수 있는지 그 필요성을 밝혀 궁극적으로 도시계획정보시스템의 발전방향을 모색하는 데 본 연구의 목적이 있다.

• Journal of the Korean Chemical Society
• /
• v.60 no.2
• /
• pp.137-143
• /
• 2016

Effective teaching and learning is a continuous process of monitoring and re-organization of teaching method, so to benefit both students and educators. Reflective journal writing is an effective method for students to reflect on their learning experience about a new concept or subject taught and at the same time enables educators to improve on their academic skills. In the present paper, we have examined and evaluated the effectiveness of the Uncritical Inference Test (UIT) that was conducted in our basic organic chemistry course through a systematic network built based on students’ reflective writing. From the data analysis, the UIT has benefited students in three dimensions, namely cognitive, affective and group learning domains. Moreover, the UIT activity instilled an active learning environment in organic chemistry classroom and deeper learning among chemistry students as shown in the collected data. In future, this activity could be adapted as a teaching method to enhance students’ critical thinking skills and question-asking capability in other teaching courses.

• Journal of Information Processing Systems
• /
• v.19 no.1
• /
• pp.55-66
• /
• 2023

Community portraits can deeply explore the characteristics of community structures and describe the personalized knowledge needs of community users, which is of great practical significance for improving community recommendation services, as well as the accuracy of resource push. The current community portraits generally have the problems of weak perception of interest characteristics and low degree of integration of topic information. To resolve this problem, the reader community portrait method based on the thematic and timeliness characteristics of interest labels (UIT) is proposed. First, community opinion leaders are identified based on multi-feature calculations, and then the topic features of their texts are identified based on the LDA topic model. On this basis, a semantic mapping including "reader community-opinion leader-text content" was established. Second, the readers' interest similarity of the labels was dynamically updated, and two kinds of tag parameters were integrated, namely, the intensity of interest labels and the stability of interest labels. Finally, the similarity distance between the opinion leader and the topic of interest was calculated to obtain the dynamic interest set of the opinion leaders. Experimental analysis was conducted on real data from the Douban reading community. The experimental results show that the UIT has the highest average F value (0.551) compared to the state-of-the-art approaches, which indicates that the UIT has better performance in the smooth time dimension.

• The Mathematical Education
• /
• v.13 no.2
• /
• pp.6-10
• /
• 1974

We consider 'ordinary' graphs: that is, finite undirected graphs with no loops or multiple edges. An intersection representation of a graph G is a function r from V(G), the set of vertices of G, into a family of sets S such that distinct points $\chi$$_{\alpha}$ and $\chi$$_{\beta}$/ of V(G) are. neighbors in G precisely when ${\gamma}$($\chi$$_{\alpha}$)∩${\gamma}$($\chi$$_{\beta}$/)$\neq$ø, A graph G is a rigid circuit grouph if every cycle in G has at least one triangular chord in G. In this paper we consider the main theorem; A graph G has an intersection representation by arcs on an acyclic graph if and only if is a normal rigid circuit graph.uit graph.d circuit graph.uit graph.

• The Korean Journal of Air & Space Law and Policy
• /
• v.4
• /
• pp.107-137
• /
• 1992

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.3
• /
• pp.307-312
• /
• 2012

This study aims to investigate the effect of the post weld treatments on the fatigue life of T-type welded structure made by a SM50A steel material, generally used for excavators, because changes in the geometry, material and surface properties of welded regions affect the fatigue life of welded structures. T-type test specimens were prepared by the CO2 welding of rolled steel plates (SM50A steel) with a thickness of 10 mm at a welding speed of 30 cm/min and these Ttype welded specimens were further treated by UIT (Ultrasonic Impact Treatment) and/or toegrinding post welding treatment methods. In order to investigate improvements on the fatigue life of the samples. 3-point bending fatigue tests were conducted with a stress ratio of R=0.1 under a cyclic loading environment at a frequency of 5 Hz, via a hydraulic fatigue testing machine (${\pm}100\;kN$, MTS 809). The tests were performed at room temperature. The fatigue life of UIT specimens was approximately 25 times longer than that of as-welded specimens at a stress amplitude of 281 MPa, while toe-grinding specimens exhibited 4.15 times longer fatigue life. The current results could provide important guidelines to determine the proper post weld treatment methodologies of T-type welded parts for excavators with a satisfactory fatigue life although under severe operating conditions.