• Proceedings of the KSR Conference
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• 2004.06a
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• pp.967-973
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• 2004

Rock socketed drilled shafts transfer significant portion of structural loads at the socketed part. Therefore, a proper design of side and base resistances of a shaft at the socket is a major concern for the geotechnical engineers. In this study, we modified the Hoek-Brown criterion to estimate side resistance of rock socketed drilled shafts. Earlier method to compute side resistance of a shaft is linear or power functions of intact rock masses. However, side resistance is mobilized like shearing which influenced by the mechanical properties of concrete and rock masses, adhesion of rock/concrete interface, roughness of rock socket. Therefore, a single coefficient or power of uniaxial compressive strength of intact rock cannot provide accurate values of side resistance in a wide range of the uniaxial compressive strength. A new approach proposed in this study can consider in situ rock mass condition (frequency or discontinuities, weathering condition), and rock types thus, it has a wider applicability than the earlier models.

• Journal of Korea Multimedia Society
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• v.8 no.11
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• pp.1483-1495
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• 2005

TCP/IP is the most commonly used protocol to communicate among servers, and is used in a wide range of applications. Unfortunately, Data transmission through TCP/IP places a very heavy burden on host CPUs. And it hardly makes another job to be processed. So, TOE(TCP/IP Offload Engine) is considered in many servers. But, most of TOE modules tends to not support binary compatibility for standard socket interfaces. So, it has problems that existing applications should be modified and recompiled to get advantage of TOE device. In this paper, to resolve upper problems, we suppose design and implementation of TOE module supporting binary compatibility for standard socket interfaces. Also, it can make a usage of multiple TOEs and NICs simultaneously.

• Journal of IKEEE
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• v.25 no.2
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• pp.315-321
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• 2021

In this paper, we have developed the multiple channel measurement system for IC Socket Test. The one can test the current-voltage measurements for pitting the several device specification, which analyze the thin current from several ㎂ to 5A with very low resistor mΩ. The increasement of the IC socket channel with lead pitch under 0.25 mm be need to perform several functions, concurrently. The system to perform these functions be designed to integrate several SMU(source measure unit) on board. So, we can reduce the 2 minutes test time per channel point to 40 sec, with daisy chain test method. Using by graphic interface, I-V curve mode and data logging technologies, we can implement the test flow methods and can make economies the time and cost.

• Journal of the Korean Geotechnical Society
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• v.20 no.1
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• pp.5-12
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• 2004

The purpose of this paper is to make an understanding of fundamental mechanism of shear behaviour between rock and concrete interfaces in the pile socketed into granite. The interface of pile socketed in rock can be modeled in laboratory tests by resolving the axi-symmetric pile situation into the two dimensional situation under CNS(constant normal stiffness) direct shear condition. In this paper, the granite core samples were used to simulate the interface condition of piles socketed in granite in our country. The samples were prepared in the laboratory to simulate field condition, roughness(angle and height), stress boundary condition, and then tested by CNS direct shear tests. This paper describes shearing behaviour of socket piles into domestic granite through the analysis of CNS test results. It was found out that the peak shear strength increases with the angle of asperity and CNS value, and also the dilation increases with the angle of asperity but decreases with the CNS value.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.737-740
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• 1998

Under the worldwide booming internet environment, there has been increasing demand for various multimedia services. Especially the demand for effective video services has been rapidly increased. In this paper, we describe the implementation of video service system for internet use based on H/263 video compression technique and UDP socket on the TCP/IP environment. In addition, by using the plug-in-play technique, the implemented system improved user interface for correct retrieval and easy usage.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.6
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• pp.326-336
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• 2006

Due to the evolution of wired and wireless communication technologies and the Internet, multimedia services such as Internet broadcast and VOD have been prevalent recently. RTP is designed to be suitable for transmission of real-time multimedia data on the Internet by IETF While a variety of applications have utilized different RTPs implemented as a library, embeddedRTP is RTP-based kernel-level protocol that resolved performance issues of this kind of RTPs. This paper proposes the ExtendedERTP protocol based on existing embeddedRTP. This new protocol resolves a couple of issues such as packet processing overhead and buffer requirement and combines its APIs with BSD socket APIs which have been widely utilized in network applications. This paper demonstrates that this integration makes it possible to transmit real-time multimedia data through the accustomed interface of BSD socket APIs with nominal extra overhead. This paper also proposes a scheme for improving packet processing time by 15$\sim$20% and another scheme for reducing memory requirement for packet processing to about 3.5%, comparing with those of embeddedRTP.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.3
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• pp.475-482
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• 2001

In this paper, I describe the implementation of the distributed lists based on socket and on RMI(Remote Method Invocation). First, I describe and implement an interface of distributed list based on socket using object stream in a distributed environment, when encapsulating the message in the distributed list. Second, the major purpose to implement a distributed list in RMI is to compare advantages and disadvantages with other networking mechanisms by implementing complicated applications. The major advantage in using RMI is to implement simply the programs without using application-level protocol. In terms of program efficiency, the applications using HMI can degrade the performance due to many TCP/IP connections generated every update. TCP/IP connection requires much less cost than RMI. Even though RMI has the mechanism processing many method calls using a sing]e network connection, RMI is less efficient than the direct use of socket. However, RMI makes it possible to communicate beyond firewall using HTTP proxying mechanism. Consequently, I present a modeling of networking mechanism in finding out optimization solution by comparing and analyzing the two systems.

• Journal of Aerospace System Engineering
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• v.12 no.2
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• pp.37-45
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• 2018

A two-axis gimbal-type antenna for a Compact Advanced Satellite (CAS) is used to efficiently transmit high resolution image data to a ground station. In this study, we designed the structure of a two-axis gimbal-type antenna while applying a launch lock device to secure its structural safety under a launch environment. To validate the effectiveness of the structural design, a structural analysis of the antenna was performed. First, a modal analysis was performed to investigate the dynamic responses of the antenna with and without the mechanical constraints of the launch lock device. In addition, a quasi-static analysis was performed to confirm the structural safety of the antenna structure and bolt I/Fs between the antenna base and the satellite. The suitable range of constraint force on the launch lock device was also determined to ensure the structural safety and mechanical gapping of the ball & socket interfaces, which places multi-constraints on the azimuth and elevation stage of the antenna.

• Journal of the Korean GEO-environmental Society
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• v.9 no.4
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• pp.5-13
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• 2008

Just as infill material can reduce the shear strength of a rock joint, a layer of soft material between concrete and the surrounding rock socket can reduce pile shaft resistance of drilled shafts socketed in rocks. This can also result from construction methods that leave smeared or remoulded rock or drilling fluid residue on the sides of the rock sockets after concrete placement. The nature of the interface between the concrete pile shaft and the surrounding rock is critically important to the performance of the pile, and is heavily influenced by construction practice. Characteristics of the concrete-rock interface, such as roughness and the presence of the soft materials deposited during or after construction can significantly affect the shaft resistance response of the pile. In this study, we conducted the parametric study to examine the performance characteristics of drilled shafts socketed in smeared rock under the vertical load with the code of finite difference method of FLAC 2D. As the results of the current research, the parameters that affect the settlement of the pile head and the ultimate unit shaft resistance could be identified.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.79-84
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• 1998

This paper describes implementation of the core DSM-CC UU interface. It briefly describes the reference model for the DSM-CC and related standards that should be reviewed for the implementation. The Common Object Request Broker Architechture, Revision 2.0 (CORBA 2.0) is sued as a remote procedure call (RPC) scheme for the UU Interface. Entire system was implemented with C++ on Windows NT platforms. The implementation procedure has been decomposed ito two tasks. The first task is to implement the Naming Service for service navigation. The Naming Service is one of the CORBA Services that extend the core CORBA specification. A client GUI is implemented for easy navigation among various services. The second task is to construct multimedia server and client for a Video-on-Demand (VoD) system. MPEG-2 Transport Stream is transported via ATM AAL5 using the Windows Socket 2.2 ATM extension API. A GUI enables the user to navigate the service domain and select a program. After the selection the user can control the MPEG-2 stream with VCR-like buttons.