• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.7
• /
• pp.3041-3063
• /
• 2018

Community search aims at finding a meaningful community that contains the query node and also maximizes (minimizes) a goodness metric. This problem has recently drawn intense research interest. However, most metric-based algorithms tend to include irrelevant subgraphs in the identified community. Apart from the user-defined metric algorithm, how can we search the natural community that the query node belongs to? In this paper, we propose a novel community search algorithm based on the concept of the k-hop and local distance dynamics model, which can naturally capture a community that contains the query node. The basic idea is to envision the nodes that k-hop away from the query node as an adaptive local dynamical system, where each node only interacts with its local topological structure. Relying on a proposed local distance dynamics model, the distances among nodes change over time, where the nodes sharing the same community with the query node tend to gradually move together, while other nodes stay far away from each other. Such interplay eventually leads to a steady distribution of distances, and a meaningful community is naturally found. Extensive experiments show that our community search algorithm has good performance relative to several state-of-the-art algorithms.

• Journal of Energy Engineering
• /
• v.23 no.4
• /
• pp.73-88
• /
• 2014

Various studies on the critical flow models for sub-cooled and/or saturated water were reviewed, especially on Fauske, Moody, and Henry for basic theoretical models; Zaloudek for insight into physical phenomena for a critical flow in an orifice type flow path; Sozzi & Sutherland for a critical flow test of saturated and sub-cooled water at high pressure for orifice and nozzles; and a Marviken test on a full-scale critical flow test. In addition, critical flow tests of sub-cooled water for the break simulators in integral effect test (IET) facilities were also investigated, and a hybrid concept using Moody's and Fauske's models was considered by the authors. In the comparison of the models for the selected test data, discussions of the effect of the diameters, predictions of the critical flow models, and design aspects of break simulator for SBLOCA scenarios in the IET facilities were presented. In the effect of diameter on the critical flow rate with respect to all dimensional scales, it was concluded that the effect of diameter was found irrespective of diameter sizes. In addition, the diameter effect on slip ratio affecting the critical flow rate was suggested. From a comparison of the critical flow models and selected test data, the Henry-Fauske model of the MARS-KS code was found to be the best model predicting the critical flow rate for the selected test data under study.

• Journal of KSNVE
• /
• v.8 no.3
• /
• pp.542-552
• /
• 1998

The noise sources, structure-borne and/or air-borne, in machinery can be defined by their locations and strengths. However the locations of that noise sources are well known in many cases. In those cases, the problem can be defined as an inverse problem to known the strengths of the noise sources in the frequency domain, the modeling scheme is classified by thecoherent or incoherent source. This paper expands the basic concept to the case of the complex noise sources, in which the set of coherent and incoherent noise sources are matched with the noise of a real vehicle. The error factors in the experiment and the optimal number of the monopole sources to match the real suond filed are also investigated. The results of the noise source modeling of heavy machinery show that the incoherent and coherent/incoherent source models are applicable to the high frequency and the low frequency region, respectively. The noise source model also enables the noise source analysis to rank the contribution of real source group such as engine, T/M, exhuast, etc.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.9 s.114
• /
• pp.904-911
• /
• 2006

A modified energy method for the fretting wear of the steam generator tube is proposed to calculate the wear-out depth between the nuclear steam generator tube and its support. Estimation of fretting-wear damage typically requires a non-linear dynamic analysis with the information of the gap velocity and the flow density around the tube. This analysis is very complex and time consuming. The basic concept of the energy method is that the volume wear rate due to the fretting-wear phenomena Is related to work rate which is time rate of the product of normal contact force and sliding distance. The wearing motion is due to dynamic interaction between vibrating tube and its support structure, such as tube support plate and anti-vibration bar. It can be assumed that the absorbed work rate would come from turbulent flow energy around the vibrating tube. This study also numerically obtains the wear-out depth with various wear topologies. A new dissection method is applied to the multi-span tubes to represent the vibrational mode. It turns out that both the secondary side density and the normal gap velocity are important parameters for the fretting-wear phenomena of the steam generator tube.

• Korean Journal of Social Welfare
• /
• v.59 no.2
• /
• pp.39-64
• /
• 2007

The purpose of this study is to find out implications which can be useful for the development of user empowerment and involvement in Korean disability services. Suggested implications are based on the earlier studies about the concept and areas of user involvement. In the theoretical review, this study compared several terminologies related to user involvement. For the depth explanation, this study described wide range of earlier studies. In addition to these descriptions, this study is exploring to show integrated theoretical framework including diverse areas, major initiatives, participation levels, models of purpose on user involvement. And to grasp ostensive understanding on specific mechanisms on participation practice, this study discussed various issues on basic assumptions, areas of involvement and supportive alternatives. Based on these theoretical examination, this study introduced concrete tasks related to policy, service organization, professional education and research to activate user participation in Korean disability services.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.2
• /
• pp.57.1-57.1
• /
• 2010

The SPICA (SPace Infrared Telescope for Cosmology & Astrophysics) is a next generation infrared space telescope being prepared by JAXA, ESA and other international collaborators. We propose to develop FPC (Focal Plane Camera) consisting of two near-infrared cameras: FPC-G (I band) for focal plane guidance and FPC-S (0.7 - 5 um) for a back-up of FPC-G and a NIR instrument for scientific observations. In this talk, we introduce the requirement and the design concept of the FPC as well as the development strategy of the project.

• Journal of architectural history
• /
• v.1 no.2 s.2
• /
• pp.116-136
• /
• 1992

Architectural essence of John Ruskin's discourse can resolve itself into natural beauty, craftmanship, and truth in structure, surface, and process. His theories became disciplines of modern English school, Art and Craft and Free architecture, in aspects of organic architecture, morality, and rationality. These concepts disseminated continental Art Nouveau and also became it's basic principles. But his empirical theories hated use of machine, and should find a ideal model in medieval romanticism of Gothic. Anti-machine, as a instictive guideline of English modern architecture, couldn't cope with the industrialization of 20th century, and Gothic revival interfered with creating a new style. Muthesius' discourses were taught by the power of group movements and modern concept of form in English school, originally by Ruskin. But he accepted the potentiality of machine and mass production, and stressed creating the new German style suitable with machine. With the progress of Deutscher Werkbund, his theories were advanced to 'quality' connected with craftmanship, to discourse on mechanical 'form', and lastly to 'standardization and type' for mass production. Mechanical functionalism of Muthesius and DWB were sophiscated and handed down to Bauhaus, and then finally helped establishment of the Modern Architecture and Internationalism. Both English and German modern architecture owed their contribution as well as limitation to Ruskin and Muthesius as theorists. Through this comparative study, we can see the priority of theory to practice, the theoretical justification based on insight for its society and future, and the practical character of theory itself.

• Journal of architectural history
• /
• v.21 no.1
• /
• pp.65-81
• /
• 2012

This is a study concerning about the definition of the concept of industrial heritage being mentioned often lately, and considering the term's origin and changing process aiming at clarifying and improving its undertone and understanding. Especially, it's a basic study to make people understand fundamentally what industrial heritage means and differences in Korea in where any innovative affair such as industrial revolution has never occurred. Looking into the origin and changing process of the industrial archaeology & industrial heritage terms, their concepts appear ambiguously defined due to their generational, phenomenal and terminological reason. but it's detectable that their subjects and timing range have been extended. Korea, China and Japan, the Asian nations also have gone through mainly phenomenal and terminological mess in accepting the terms. Korean industrial heritage can define from the definition of industrial heritage in Nyzni Tagil charter. It, however, have to redefine about period of industrialization. This study suggest the 4 steps of modern industrialization in Korea and insist that we have to conserve industrial heritages not only in colonial period but also in 1960-80 industrialization in korea.

• Journal of Environmental Health Sciences
• /
• v.28 no.2
• /
• pp.23-39
• /
• 2002

This study focuses on the structure of geographical conditions, the riverbed, the meterological and atmospheric examination, the ecological environment, the food chain and the ecosystem, in order to establish a basic plan for preparing a natural learning area of environmental ecosystem in Bukchun and its surroundings, Gyeongju. The results could be summarized as follows. Bukchun is a first grade which extends 6km along the road from Bomun bridge to the junction of Hyungsangang. The basin area is 7.10$\textrm{km}^2$ and the slope is 1/200~1/300. Gyeongju has good atmospheric conditions, i.e. SO$_2$0.011 ~0.017ppm, CO 0.8~ 1.5ppm, NO$_2$0.013~0.019ppm, $O_3$0.013~0.020ppm, TSP 85~142$\mu\textrm{g}$/㎥, PM-10 47~90$\mu\textrm{g}$/㎥ and Pb 0.057 ~0.129$\mu\textrm{g}$/㎥, which is below the annual and daily averages, and is little lower than those of Pohang and Ulsan. The ecosystem of Bukchun is based on the structure of the food chain, which includes birds such as the grey and white herons at the top of the food chain. This study also considers the development of the river's in terms of culture, environment and ecology concept.

• Journal of Environmental Science International
• /
• v.26 no.1
• /
• pp.97-107
• /
• 2017

In the recent trend where crime types are being diversified along with urban expansion, we are facing the reality of a 'taking-it-out-on-somebody' crime, which targets the public rather than a specific person with criminal intent, like a 'random target crime.' A park, which is a public space for urban dwellers' and residents' leisure and rest in the midst of social changes, can be called the spot where various crimes occur. This is because it is a space without boundaries, available for the influx of many and unspecified persons, thus making it difficult to specify users. For the purpose of keeping a park safe from crime and providing users with psychological stability, this study carried out its research to get basic knowledge of the introduction of CPTED (Crime Prevention Through Environmental Design) concept in park development. The park development guideline contents are analyzed based on the six principles of CPTED theory as per the space composition element of a park. As a result, this study found out a problem was that most guidelines applied to the space composition element of a park were fragmentary in applying the six principles of CPTED theory, and were focused on arrangement and installation of facilities.