• Wind and Structures
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• v.19 no.5
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• pp.481-503
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• 2014

A new theoretical model on rain-wind induced vibration (RWIV) of a continuous stay cable is developed in this paper. Different from the existing theoretical analyses in which the cable was modeled as a segmental rigid element, the proposed scheme focuses on the in-plane and out-of-plane responses of a continuous stay cable, which is identical with the prototype cable on cable-stayed bridge. In order to simplify the complexities, the motion law of the rivulet on the cable surface is assumed as a sinusoidal way according to some results obtained from wind tunnel tests. Quasi-steady theory is utilized to determine the aerodynamic forces on the cable. Equations of motion of the cable are derived in a Cartesian Coordinate System and solved by using finite difference method to obtain the in-plane and out-of-plane responses of the cable. The results show that limited cable amplitudes are achieved within a limited range of wind velocity, which is a unique characteristic of RWIV of stay cable. It appears that the in-plane cable amplitude is much larger than the out-of-plane cable amplitude. Rivulet frequency, rivulet distribution along cable axis, and mean wind velocity profile, all have significant effects on the RWIV responses of the prototype stay cable. The effects of damping ratio on RWIVs of stay cables are carefully investigated, which suggests that damping ratio of 1% is needed to well mitigate RWIVs of prototype stay cables.

• Journal of Information Science Theory and Practice
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• v.12 no.2
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• pp.22-35
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• 2024

There has been a growing interest in halal-related ontology research in recent years, as ontology has gained recognition in the halal industry. This paper discusses the development of a flavouring ontology that will assist halal management auditors in predicting the halal status of flavours in order to process food producers' applications for halal certification. The development of a flavouring ontology is based on multiple references, because the auditors of halal management divisions must consult a variety of sources independently in order to determine the halal status of flavourings. The process includes 1) determining the ontology goal and scope, 2) building ontologies, and 3) evaluating the ontologies. The researcher used Protégé to design the ontologies, and Phyton was used to develop a prototype based on flavouring ontology. The developed ontology consists of four classes, nine sub-classes, and 11 relationships. The evaluation of the ontology using the prototype revealed that the majority of experts were satisfied with the information generated by the ontology in the prototype, particularly in relation to synonyms and the hierarchical structure of a flavour. However, the experts suggest improvements in terms of flavour metadata, especially on raw materials and natural occurrence data, so that the flavour information retrieved is comprehensive and accurate.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.351-358
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• 2006

In this paper, the electrical characteristics of the contactless transformer is presented using the conventional coupled inductor theory. Compared with the conventional transformer, the contactless transformer has a large airgap, long primary wire and multi-secondary wire. As such, the contactless transformer has a large leakage inductance, small magnetizing inductance and poor coupling coefficient. Therefore, large magnetizing currents flow through the entire primary system due to small magnetizing inductance, resulting in low overall system efficiency. In high power applications, the contactless transformer is so bulky and heavy that it needs to be split by some light and small transformers. So, the contactless transformer needs several small transformer modules that are connected in series or parallel to transfer the primary power to the secondary one. This paper shows the analysis and measurement results of each contactless transformer module and comparison results between the series- and parallel-connection of the contactless transformer. The results are verified on the simulation based on the theoretical analysis and the 30kW experimental prototype.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.3
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• pp.57-68
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• 2012

In this study, designs of the high efficiency composite propeller blade for a high speed turboprop aircraft, which will be used for a next generation regional commercial aircraft in Korea, are performed. Both the vortex theory and the blade element theory are used for preliminary aerodynamic design and performance analysis of the propeller. Then the aerodynamic design result is confirmed through performance analysis using a commercial CFD code, ANSYS. The carbon/epoxy composite materials is used, and the skin-spar-foam sandwich type structure is adopted for improvement of lightness and structural stability. Finally, it is investigated that the proposed propeller blade has high efficiency and structural safety through both aerodynamic and structural analysis and experimental test of a prototype propeller blade.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.11
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• pp.1326-1331
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• 2009

The sensor data measured by the legged robot are used to recognize the physical environment or information that controls the robot's posture. Therefore, a robot's ambulation can be advanced with the use of such sensing information. For the precise control of a robot, highly accurate sensor data are required, but most sensors are expensive and are exposed to excessive load operation in the field. The seriousness of these problems will be seen if the prototype's practicality and mass productivity, which are closely related to the unit cost of production and maintenance, will be considered. In this paper, the use of a virtual sensor technology was suggested to address the aforementioned problems, and various ways of applying the theory to a walking robot obtained through training with an actual sensor, and of various hardware information, were presented. Finally, the possibility of the replacement of the ground reaction force sensor of legged robot was verified.

• Journal of Communications and Networks
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• v.12 no.3
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• pp.266-274
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• 2010

The efficient network resource management is one of the important topics in a real-time system. In this paper, we present a practical network resource management framework, control-theoretic packet scheduler (CPS) system. Using our framework, an operating system can schedule both input and output streams accurately and efficiently. Our framework adopts very portable feedback control theory for efficiency and accuracy. The CPS system is able to operate independent of the internal network protocol state, and it is designed to schedule packet streams in fine-grained time intervals to meet the resource requirement. This approach simplifies the design of the CPS system, and leads us to obtain the intended output bandwidth. We implemented our prototype system in Linux, and measured the performance of the network resource management system under various network QoS constraints. The distinctive features of our principles are as follows: It is robust and accurate, and its operation is independent of internal network protocols.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.253-258
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• 2012

In this study, designs of the high efficiency composite propeller blade for a high speed turboprop aircraft, which will be used for a next generation regional commercial aircraft in Korea, are performed. Both the vortex theory and the blade element theory are used for preliminary aerodynamic design and performance analysis of the propeller. Then the aerodynamic design result is confirmed through performance analysis using a commercial CFD code, ANSYS. The carbon/epoxy composite materials is used, and the skin-spar-foam sandwich type structure is adopted for improvement of lightness and structural stability. Finally, it is investigated that the proposed propeller blade has high efficiency and structural safety through both aerodynamic and structural analysis and experimental test of a prototype propeller blade.

• Korean Journal of Social Welfare
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• v.65 no.1
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• pp.109-126
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• 2013

This paper aims to define Mecius's people-care theory(保民論), and aims to recognize the characteristics of social security contained in Mecius's people-care theory. Mecius considered to the public relief as King's obligation. So to speak, the King protects to the property of the people. Especially his people-care theory implicate to continuity of safety life, a relief fund on the property, protection of disaster damage. Continuity of safety life means to enabling the people procurable food, clothing and bury dead persons without difficulties. It's may be said that implicated to the theory and system of modern social-welfare. It is reason for his opinion that a state should construct in the minimum social safety network by taking responsibility for basis needs of life. He was a humanist so much. He thought about the pursuit of the human happiness and the improvement in quality of life. Therefore his idea nearly means to the social security system in a modern sense. His thought is not only an ideal background on the public assistance and a social relief security in the contemporary but also a relief activity system such as Jindaebup called historical prototype of social welfare. It is an important fact that his people-care theory implicate to social security system.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.5
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• pp.257-266
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• 2006

Recently TCP/IP Offload Engine (TOE) technology, which processes TCP/IP on a network adapter instead of the host CPU, has become an important approach to reduce TCP/IP processing overhead in the host CPU. There have been two approaches to implementing TOE: software TOE, in which TCP/IP is processed by an embedded processor on a network adapter; and hardware TOE, in which all TCP/IP functions are implemented by hardware. This paper proposes a hybrid TOE that combines software and hardware functions in the TOE. In the hybrid TOE, functions that cannot have guaranteed performance on an embedded processor because of heavy load are implemented by hardware. Other functions that do not impose as much load are implemented by software on embedded processors. The hybrid TOE guarantees network performance near that of hardware TOE and it has the advantage of flexibility, because it is easy to add new functions or offload upper-level protocols of TCP/IP. In this paper, we developed a prototype board with an FPGA and an ARM processor to implement a hybrid TOE prototype. We implemented the hardware modules on the FPGA and the software modules on the ARM processor. We also developed a coprocessing mechanism between the hardware and software modules. Experimental results proved that the hybrid TOE prototype can greatly reduce the load on a host CPU and we analyzed the effects of the coprocessing mechanism. Finally, we analyzed important features that are required to implement a complete hybrid TOE and we predict its performance.

• The Korean Journal of Coaching Psychology
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• v.7 no.3
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• pp.127-152
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• 2023

Employees' innovative behavior is crucial for organizations to maintain competitiveness and foster growth. Empowering leadership coaching styles, which delegate authority and responsibility to organizational members while respecting their autonomy, create opportunities for members to solve problems and present innovative ideas. Drawing on signal theory, this study aims to clarify the process through which political skill influences employees' work innovative behavior, mediated by empowering leadership. Additionally, we examine whether the leader's implicit followership prototype moderates the relationship between employees' political skills and empowering leadership. Survey data were collected in two rounds with a two-week lag from 180 employees in a manufacturing company in South Korea. The results revealed that political skill was related to empowering leadership and subsequent work innovative behavior. Furthermore, the leaders' implicit followership prototype strengthened the relationship between political skill and empowering leadership. This study provides meaningful theoretical and practical insights into empowering coaching styles.