• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.1
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• pp.20-28
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• 2014

In this paper, based on the characteristics of proportional navigation, a composite guidance law is proposed for impact angle control of passive homing missiles maintaining the lock-on condition of the seeker. The proposed law is composed of two guidance commands: the first command is to keep the look angle constant after converging to the specific look angle of the seeker, and the second is to impact the target with terminal angle constraint and is implemented after satisfying the specific line of sight(LOS) angle. Because the proposed law considers the seeker's filed-of-view(FOV) and acceleration limits simultaneously and requires neither time-to-go estimation nor relative range information, it can be easily applied to passive homing missiles. The performance and characteristics of the proposed law are investigated through nonlinear simulations with various engagement conditions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.9
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• pp.742-751
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• 2018

In this paper, we propose a time varying biased proportional navigation guidance law that controls the impact angle under Field-of-View(FOV) and the acceleration limit of the missile. The proposed law is composed of three stages in consideration of the FOV limitation. Since the bias directly affects the acceleration at each stage, the final bias value of the previous stage becomes the initial bias value of the next stage when the stage is switched. In addition, the impact angles were controlled by judging whether impact angles were reached in consideration of engagement conditions and physical constraints.

• The KIPS Transactions:PartD
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• v.17D no.1
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• pp.25-40
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• 2010

Service-Oriented Architecture (SOA) is a development paradigm for reusing services as an independent reuse unit. A service delivers a cohesive functionality through its external interface. Since services have unique characteristics which are not typically presented in conventional development approaches, there is a demand for effective approaches to developing services. Most of the current SOA methodologies presenta process where services are designed and developed from the requirements rather than reusing existing assets, which demands high cost and effort. Hence, a desirable approach is to be able to develop services by migrating from their existing legacy systems such as object-oriented system. A difficulty in this migration is that objects in object-oriented systems reveal characteristics which differ considerably from those of services. That is, objects are designed without considering commonalities among several consumers. In this paper, we first define mapping relationships between key artifacts in object-oriented system and those in SOA services. By these relationships and considering commonalities among several applications in a domain, we propose three systematic methods to migrate from object-oriented system to SOA services. Each method consists of a list of input and output artifacts and detailed guidelines which are performed in order. Through these methods, service developers can easily develop services with less effort.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.222-232
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• 2012

This study was conducted to compare the task-oriented exercise and weight-shifting exercise program has effectiveness on the static and dynamic balance in patients with total knee replacement. The participants were allocated randomly into 2 group : task-oriented exercise group(n=12) and weight-shifting exercise group(n=12). To evaluate the effects of exercise, subjects were evaluated by using Gaitveiw System and functional reaching test for static balance and Balance System for dynamic balance test. The data was analyzed using a paired t-test and independent t-test to determine the statistical significance. Static balance test and dynamic balance test in task-oriented exercise had statistical significance than weight-shifting exercise program(p<0.05). So this results were suggested that the task-oriented exercise was effective on static and dynamic balance in patients with total knee replacement.

• Journal of Technology Innovation
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• v.22 no.4
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• pp.57-88
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• 2014

The 'Grand Challenge' in the global level raises fundamental questions on the role of private firm as a profit maximizer. From the new perspective, firms are recognized as a social entity with social and environmental responsibility. Particularly, the importance of transition-orineted firms, which pursue an objective of socio-technological system transition, have increased. These environmental changes request a new understanding on the identification of firms and the evolution of sustainable business model from the technological innovation perspectives. This paper aims on the new understanding on the motivation of firms who participated on the sustainable system transition and the proposal of 'transition-oriented firms' concept. Based on literature survey, this paper reviews the role of firms in the process of socio-technological system transition, the cases of transition-oriented firm, the types of sustainable business models and their strategies.

• Journal of The Korean Association of Information Education
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• v.22 no.2
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• pp.177-193
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• 2018

The purpose of this paper is to explore the types of subjectivity on edutainment features of software education implemented in elementary school. Q-method is used to seek individual learners' subjectivity type. Three types of subjectivity are found: implementation type, intellectual-fun type, and relationship type. Implementation type learners show positive attitude toward making their thinking into realization, intellectual-fun type learners show positive attitude toward solving problems that require intellectual activities, and relationship type learners show positive toward other persons' attention and consideration. These results imply software education will be more enhanced with these three types considered for implementing software education in elementary schools. This study is expected to contribute to further following research and practices.

• Journal of the Korean association of regional geographers
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• v.9 no.3
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• pp.349-372
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• 2003

The location of tourist function is influenced by the accessibility of fishing villages and tourist potential in the villages. In Jeju island, the accessibility of fishing villages is not enough of a difference, therefore tourist potential in the villages has a dominant influence on the tourist location. In the location of the tourist function, there is all the difference between sea or land. Because sea and land are a remarkable contrast in physical condition and tourist activity space. Consequently, the basic types of the tourist location are sea-oriented, land-oriented, sea land-oriented. Besides, fishing villages adjacent to the beach and islands are to be the types of the tourist location. The former is not central fishing village in the tourist location, the latter is not good in the accessibility of the basic three types. And the location of the tourist function has a dominant influence on the difference of tourist fishing villages, therefore the types of the tourist location is to be the types of tourist fishing villages.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.708-711
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• 2008

This study is intended to build research for ways to utilize material information in the design and working business for public works. The contents and results of this study can be classified into object-oriented DB application to bridge construction and object-oriented DB utilization of civil material information. First, application of object-oriented DB to bridge construction 1) constructs the work unit of classified work table as an object(Each object constructs material information on the statement of quantity calculation as data), 2) constructs object-oriented DB for superstructure and substructure of PSC Beam bridge, 3) leads to the research for ways to utilize materials by developing 3D bridge prototype with REVIT structure. Secondly, ways to utilize object-oriented DB for civil material information identified the possibility for utilizing it in making 2D drawings for design work, preparing materials list, analyzing structure for working businesses, selecting and purchasing materials, managing process and maintaining. It is suggested that the results of this study should be applied to all bridge constructions through test-bed and additional studies so as to secure the credibility of the results of this study.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.853-860
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• 2001

In the object-oriented software development, redesigning of classes and reorganizing of class hierarchy structures should be necessary to reduce many of the headaches of object-oriented software design and maintenance. To support this task, in this paper, we propose a theoretical foundation for class hierarchy reorganizations that is relatively complete, correct, formal and easy to understand and use. We introduce the flattened class hierarchy that characterizes the class hierarchy structures in object-oriented software evolution. And we also present an algorithm which transforms a given class hierarchy into the normalized form. The flattened class hierarchy helps us map the inheritance and aggregation paths in a class hierarchy to paths in an object hierarchy that is an instance of the class hierarchy. By applying the algorithm into a given class hierarchy, we can make a new, object-preserved, and flattened class hierarchy that is the cornerstone for reorganization of class hierarchy structure and plays an important role as a bridge on the incremental evolutionary changes and reuse of object-oriented software to reorganize class hierarchies.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.419-429
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• 2021

The purpose of this study is to investigate the effects of service guarantees of tourist hotels on employees' perception of role clarity and customer orientation. Specifically, this study analyzed how the employees' perception of role clarity as a parameter, with the employees' reliability, guarantee-related communication, guarantee limitation, and organizational support as independent variables, affected the dependent variable, customer orientation. As a result of empirical analysis of employees in the first grade hotel in Seoul, it was analyzed that the higher the reliability of employees in service guarantee, the higher the communication and organizational support in the organization related to guarantee work, the higher the role clarity and perception level of employees. The higher the reliability, guarantee limitation and organizational support level of guarantee, the higher the customer orientation, but the guarantee-related communication did not show significant influence. The perception degree of role clarity of employees has a significant effect on customer orientation. According to those results of this analysis, this study examined the influence of each configuration of service guarantee of tourist hotel employees on customer orientation, and presented various academic and practical implications.