• Honam Mathematical Journal
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• v.34 no.4
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• pp.559-570
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• 2012

We construct a new definition of a base for ordinary smooth topological spaces and introduce the concept of a neighborhood structure in ordinary smooth topological spaces. Then, we state some of their properties which are generalizations of some results in classical topological spaces.

• Coupled systems mechanics
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• v.1 no.3
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• pp.235-245
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• 2012

The nonlinear resonant response of an axially moving beam is investigated in this paper via two different numerical techniques: the pseudo-arclength continuation technique and direct time integration. In particular, the response is examined for the system in the neighborhood of a three-to-one internal resonance between the first two modes as well as for the case where it is not. The equation of motion is reduced into a set of nonlinear ordinary differential equation via the Galerkin technique. This set is solved using the pseudo-arclength continuation technique and the results are confirmed through use of direct time integration. Vibration characteristics of the system are presented in the form of frequency-response curves, time histories, phase-plane diagrams, and fast Fourier transforms (FFTs).

• Asia pacific journal of information systems
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• v.8 no.1
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• pp.43-64
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• 1998

Cooperative query answering is a research effort to develop a fault-tolerant and intelligent database system using the semantic knowledge base constructed from the underlying database. Such knowledge base has two aspects of usage. One is supporting the cooperative query answering process for providing both an exact answer and neighborhood information relevant to a query. The other is supporting ongoing maintenance of the knowledge base for accommodating the changes in the knowledge content and database usage purpose. Existing studies have mostly focused on the cooperative query answering process but paid little attention to the dynamic knowledge base maintenance. This paper proposes a multi-level knowledge representation framework called Knowledge Abstraction Hierarchy(KAH) that can not only support cooperative query answering but also permit dynamic knowledge maintenance, On the basis of the KAH, a knowledge abstraction database is constructed on the relational data model and accommodates diverse knowledge maintenance needs and flexibly facilitates cooperative query answering. In terms of the knowledge maintenance, database operations are discussed for the cases where either the internal contents for a given KAH change or the structures of the KAH itself change. In terms of cooperative query answering, four types of vague queries are discussed, including approximate selection, approximate join, conceptual selection, and conceptual join. A prototype system has been implemented at KAIST and is being tested with a personnel database system to demonstrate the usefulness and practicality of the knowledge abstraction database in ordinary database application systems.

• International Journal of Automotive Technology
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• v.7 no.5
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• pp.535-545
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• 2006

A nonlinear analysis of torsional self-excited vibration in the driveline system for wheeled towing tractors was presented, with a 2-DOF mathematical model. The vibration system was described as a second-order ordinary differential equation. An analytical approach was proposed to the solution of the second-order ODE. The mathematical neighborhood concept was used to construct the interior boundary and the exterior boundary. The ODE was proved to have a limit cycle by using $Poincar\'{e}-Bendixson$ Annulus Theorem when two inequalities were satisfied. Because the two inequalities are easily satisfied, the self-excited vibration is inevitable and even the initial slip rate is little. However, the amplitude will be almost zero when the third inequality is satisfied. Only in a few working modes of the towing tractor the third inequality is not satisfied. It is shown by experiments that the torsional self-excited vibration in the driveline of the vehicle is obvious.

• Journal of Intelligence and Information Systems
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• v.18 no.2
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• pp.131-141
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• 2012

In this paper, we propose a new method for collaborative filtering (CF)-based recommender systems. Traditional CF-based recommendation algorithms have applied constant settings such as a reference group (neighborhood) size and a significance level to all users. In this paper we develop a new method that identifies optimal personalized settings for each user and applies them to generating recommendations for individual users. Personalized parameters are identified through iterative simulations with 'training' and 'verification' datasets. The method is compared with traditional 'constant settings' methods using Netflix data. The results show that the new method outperforms traditional, ordinary CF. Implications and future research directions are also discussed.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.2
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• pp.131-156
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• 1998

Cooperative query answering is a research effort to develop a fault-tolerant and intelligent database system using the semantic knowledge base constructed from the underlying database. Such knowledge base has two aspects of usage. One is supporting the cooperative query answering Process for providing both an exact answer and neighborhood information relevant to a query. The other is supporting ongoing maintenance of the knowledge base for accommodating the changes in the knowledge content and database usage purpose. Existing studies have mostly focused on the cooperative query answering process but paid little attention on the dynamic knowledge base maintenance. This paper proposes a multi-level knowledge representation framework called Knowledge Abstraction Hierarchy (KAH) that can not only support cooperative query answering but also permit dynamic knowledge maintenance. The KAH consists of two types of knowledge abstraction hierarchies. The value abstraction hierarchy is constructed by abstract values that are hierarchically derived from specific data values in the underlying database on the basis of generalization and specialization relationships. The domain abstraction hierarchy is built on the various domains of the data values and incorporates the classification relationship between super-domains and sub-domains. On the basis of the KAH, a knowledge abstraction database is constructed on the relational data model and accommodates diverse knowledge maintenance needs and flexibly facilitates cooperative query answering. In terms of the knowledge maintenance, database operations are discussed for the cases where either the internal contents for a given KAH change or the structures of the KAH itself change. In terms of cooperative query answering, database operations are discussed for both the generalization and specialization Processes, and the conceptual query handling. A prototype system has been implemented at KAIST that demonstrates the usefulness of KAH in ordinary database application systems.

• Journal of Popular Narrative
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• v.26 no.3
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• pp.221-254
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• 2020

This paper finds a solution in the social context which cannot be explained thoroughly by well-timed release date, revival of comedy films, and the attraction of Lee Byeong-heon's comedy etc. while it throws question of how the film, Extreme Job captivated 16 million audience. The incredible hits of Extreme Job cannot be explained by analyzing the text alone. After this essay investigates a function and a role of comedy as a public sphere, it examines people's desires and wishes in the comedy and other genres since 2008 when the conservative government has seized power. Since 2008 a series of dark tone's action thriller, social problem film, and disaster film have emerged, these genres showed absence of public security, crisis of democracy and criticism against rulling class. On the other hand, hit comedy films have showed escapism such as weepie, nostalgia, and fantasy at the same time, generally. Although Veteran (2015) is not full-blown comedy, after this film's big success, "comic mode" has gradually revived. A light tone's films which are truer to genre rules has started representing the wishes of people toward social reforms and changes. Meanwhile, "Candlelight Protest" served as a momentum to recover the democracy which has been in crisis, but it could not lead changes in economic and daily lives. Exreme Job can be read as a question how we will survive since "Candlight Protest." The lives of detectives as self-employed workers who has taken over a fried chicken restaurant for going undercover are appearances of ordinary persons who must survive in the edless conpetition. Furthermore, this film shows a dream of a "great success myth" which becomes well-known as a famous restaurant and a self-management such as brand-naming and an exapansion of franchise business. We can read ganster's chicken franchises as a huge distribution industry which disturbs market system by delivering drugs secretly. While applauses that we give to the police having identities of self-employed workers which sweeps the ganster are giving support to oridinary neighborhood like us, they are also wishes of people who long for the restoration of publicness of police in the market which is becoming increasingly privatized today. A significance of this essay is to examine Extreme Job in terms of the geography of film genres and the revival of comic mode sicne 2008 at the macro level, and is to read the film in the perspective of the problems of economic and daily lives which has been still unsolved since "Candlelight Protest" at the micro level.