• Proceedings of the KWS Conference
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• 1995.04a
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• pp.133-134
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• 1995

• Proceedings of the KWS Conference
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• v.43
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• pp.174-176
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• 2004

The duplex stainless clad vessel with 38m & over thickness shall be performed to PWHT based on the ASME code. In this case, it is well-known that precipitators such as carbides and sigma($\sigma$) phase are formed at gram boundary between ferrite and austenite phase. Therefore, a weld test for simulating this situation has been planned and performed by 3309LMo71-1 for barrier layer and E2209Tl-1 for 2nd & over layer and then carried out to investigate the overlaid weld metal. Based on the test results, it could be concluded that PWHT should be carried out after the completion of 1st(barrier) layer and then 2 & over layer should be applied.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.363-366
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• 2004

The purpose of this study is to reveal the spatial relationship between landslides and geospatial data set and to map the landslide susceptibility using this relationship, and the landslide occurrence data in Kangneung area in 2002. Landslide locations were identified from interpretation of satellite images. Landslide susceptibility was analyzed using an artificial neural network. The weights of each factor were determined by the back-propagation training method. Susceptibility maps were constructed from Geographic Information System (GIS), The cases were overlaid and cross overlaid for landslide susceptibility mapping in each study area in Kangneung.

• Journal of Welding and Joining
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• v.15 no.1
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• pp.135-148
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• 1997

It was attempted to improve wear resistance and durability under the load surface pressure that make a formation of the thick (mm-order) hard-surfacing layer for aluminum alloy of 5083. The thick hard layers were formed on the surface of 5083 by TIG overlay method. Al-(25.4, 33.6, 45.7 mass%) Cu filler metals which were newly developed were overlaid on two base metals forming the one bead, one layer and two layers. The investigation was made on the characteristics of hardening and wear resistance in relation to the microstructure of overlaid layers with selection of optimum overlaying condition.

• Journal of the Korea Society of Computer and Information
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• v.22 no.8
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• pp.25-32
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• 2017

In this paper we propose a resource management method which enables to guarantee the quality of experience (QoE) for handover in the overlaid macro-femtocell networks. How to cope with the resource demand of handover calls is necessary to efficiently support the movement of mobile terminals, the QoE degradation or the load control. We attempt to satisfy the QoE requirements of users and maximize the capacity of the system at the same time. In order to achieve this goal, this scheme divides the shared resources into two part for the movement of MT and QoE degradation, and allocates those resources with the competition between four types of handovers. Simulation results show that our scheme provides better performances than the conventional one with respect to the outage probability, data transmission throughput.

• Journal of Information Processing Systems
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• v.10 no.3
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• pp.384-394
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• 2014

The femtocell overlaid cellular network (FOCN) has been used to enhance the capacity of existing cellular systems. To obtain the desired system performance, both cross-tier interference and co-tier interference in an FOCN need to be managed. This paper proposes an interference management scheme that adaptively constructs a femtocell cluster, which is a group of femtocell base stations that share the same frequency band. The performance evaluation shows that the proposed scheme can enhance the performance of the macrocell-tier and maintain a greater signal to interference-plus-noise ratio than the outage level can for about 99% of femtocell users.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.2
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• pp.394-408
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• 1996

In this paper, we classify the transfer method of overflowed traffic from microcell to macrocell in micor/macro overlaid PCS system using CDMA technology, and analyze the traffic characteristics of traffic transfer methods. Soft-handoff is charaterized by communications with a new bastation on the same CDMA frequency assignment before terminating communications with the old basestation. Therefore, soft-handoff is superior to hard-handoff with respect to Grade Of Service, but it decreases the carried traffic of system. Therefore, we analyze the effect of soft-handoff with respect to handoff area variation. In order to analyze soft-handoff effect, we resolve the probability of dewelling time in soft-handoff area, and calculates the carried traffic of microcell using this result.

• Journal of Ocean Engineering and Technology
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• v.18 no.2
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• pp.70-76
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• 2004

In the steel marking industry, most companies have adapted the continuous casting process, due to its economical benefit. Casting rolls are utilized for frictional drive and the transport of solidifying slap. Dimensional tolerances, mechanical stability, and surface condition of the casting rolls can affect both the surface and the internal quality of the product being cast. To overcome these problems, the industry now is focused on accelerating the rate of technological improvements. This study has been undertaken for the development of casting rolls overlaid materials (SAW FCW wire), with the addition of Vanadium and Molybdenum to the martensitic stainless steel, in order to increase tensile strength and hardness at elevated temperatures.

• ETRI Journal
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• v.38 no.1
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• pp.30-40
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• 2016

Co-channel interference between macro-femtocell networks is an unresolved problem, due to the frequency reuse phenomenon. To mitigate such interference, a secondary femtocell must acquire channel-state knowledge about a co-channel macrocell user and accordingly condition the maximum transmit power of femtocell user. This paper proposes a pilot-based spectrum sensing (PSS) algorithm for overlaid femtocell networks to sense the presence of a macrocell user over a channel of interest. The PSS algorithm senses the pilot tones in the received signal through the power level and the correlation metric comparisons between the received signal and the local reference pilots. On ensuring the existence of a co-channel macrocell user, the maximum transmit power of the corresponding femtocell user is optimized so as to avoid interference. Time and frequency offsets are carefully handled in our proposal. Simulation results show that the PSS algorithm outperforms existing sensing techniques, even at poor received signal quality. It requires less sensing time and provides better detection probability over existing techniques.

• Journal of IKEEE
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• v.16 no.2
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• pp.81-85
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• 2012

In this paper, we analyze the effect of mobility management method to the data rate of moving users when pico-cell which uses the same frequency bandwidth as that of macro-cell is overlaid over macro-cell. From this analysis, we show that the data rate which is available to the moving user depends on the method of mobility management and relative location of the overlaid pico-cell over macro-cell in the network.