• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.6
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• pp.139-144
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• 2019

For recent decades, Non-volatile Memory (NVM) technologies have been drawing a high attention both in industry and academia due to its high density and short latency comparable to that of DRAM. However, NVM devices has write endurance problem and thus the current data structures that have been built around DRAM-specific features including unlimited program cycles is inadequate for NVM, reducing the device lifetime significantly. In this paper, we revisit a red-black tree extensively adopted for data indexing across a wide range of applications, and make it to better fit for NVM. Specifically, we observe that the conventional red-black tree wears out the specific location of memory because of its rebalancing operation to ensure fast access time over a whole dataset. However, this rebalancing operation frequently updates the long-lived nodes, which leads to the skewed wear out across the NVM cells. To resolve this problem, we present a new swapping wear-leveling red-black tree that periodically moves data in the worn-out node into the young node. The performance study with real-world traces demonstrates the proposed red-black tree reduces the standard deviation of the write count across nodes by up to 12.5%.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.12
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• pp.39-48
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• 2001

We have studied the design of the photonic bandgap (PBG) structure on the microstrip line that can effectively control the fractional bandwidth of the passband formed in the stopband by adding the stub in the cell of the microstrip PBG structure. As the length of the stub increases, the cutoff frequency and the center frequency of the stopband are decreased, while the bandwidth of the stopband is increased. We have also found that the fractional bandwidth of the passband formed in stopband by the introduction of defect decreases as the stub length is increased. These results mean that adding the stub in the normal PBG structure is an effective way to control the fractional bandwidth. As an application example, we have implemented a microwave duplexer using the proposed structure.

• Journal of Convergence Society for SMB
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• v.6 no.3
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• pp.21-27
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• 2016

In this paper, we introduce the PB/MC-CDMA (Partial Block/Multi-Carrier-Code Division Multiple Access) system to mitigate inter-cell interference (ICI) and enhance user capacity in the small cell environment. In 5G mobile communications, the number of devices connected to the network is expected to increase exponentially with the expansion of the IoT (Internet of Things) services. In addition, each device is expected to be required by the various data rates by their content types. In LTE/LTE-A, there are some limitations that large scale connectivity and supporting various data rates. Therefore, we introduce a PB/MC-CDMA physical layer system which is suitable for the small cell environment, and evaluate the performance in the multi cell environment which is affected by ICI. Through computer simulation results, we demonstrate the effectiveness of PB/MC-CDMA for the small cell environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.4
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• pp.371-380
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• 2013

D2D (Device-to-Device) communication on an underlying cellular infrastructure which exploits the same spectrum has several advantages such as increased resource utilization and improved cellular coverage. However, D2D communication system needs to cope with ICI (Inter-Cell Interference) and interference between cellular and D2D links. As a result, macro UEs (User Equipments), especially those located near cell edge, will suffer from serious link performance degradation. We propose a novel interference avoidance mechanism assisted by SRN (Shared Relay Node) in this paper. SRN not only performs data re-transmission as a usual Type II relay but also has several features newly defined to avoid interference between cellular and D2D links. In particular, we suggest resource allocation methods based on the SRN for effective interference avoidance, and evaluate their performance through computer simulations.

• Tunnel and Underground Space
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• v.32 no.3
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• pp.219-230
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• 2022

The Geo-Reservoir Experimental Analogue Technology (GREAT) cell was designed to recreate the thermal-hydro-mechanical conditions of deep subsurface in the laboratory. This apparatus can generate a polyaxial stress field using lateral loading elements, which rotate around the longitudinal axis of a sample and is capable of performing a fluid flow test for samples containing fractures. In the present study, numerical simulations were carried out for triaxial compression tests using the GREAT cell and the mechanical behavior of samples under different conditions of lateral loading was investigated. We simulated an actual case, in which triaxial compression tests were conducted for a polymer sample without fractures, and compared the results between the numerical analysis and experiment. The surface strain (circumferential strain) of the sample was analyzed for equal and non-equal horizontal confining pressures. The results of the comparison showed a good consistency. Additionally, for synthetic cases with a fracture, we investigated the effect of the friction and type of fracture surface on the deformation behavior.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.111-119
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• 2023

Internal storage state, weight data, and weight-centered calculation values for overhead bin can all be seen in this paper's real-time internal status identification system. The suggested system offers such valuable data via a range of sensors, including load cells and switch arrays. The proposed system could locate internal free space, locate the center of gravity, and give real-time visual information. It was developed utilizing an embedded system and the C programming language. These features led to the creation of smart overhead bins and real-time cargo loading monitoring technologies, both of which could one day aid in the creation of a cargo loading automation system.

• Journal of Korea Entertainment Industry Association
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• v.15 no.8
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• pp.45-62
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• 2021

This article examines celeactor as cultural contents focused on the multi-persona in a South Korean reality show program . The celeactor is a form of celebrity and part of a celetoid. Celebrity can be categorized by three forms: ascribed form, achieved form and attributed form. In attributed form, the celetoid suddenly becomes popular through the media. The celeactor is a subcategory of the celetoid. The celeactor is defined by a virtual character that exist in temporary or institutionalized traits of popular culture. The Korean celebrity culture presents Korean intellectual factors, spiritual aspects, tastes, moral virtue, power relationships and traditional hierarchy. In order to examine the features of the Korean celeactor in cultural contents, this article focuses on the multi-persona of celebrity in South Korean popular culture through fantasy, challenge and nostalgia. This article examines the multi-persona of celebrity represented in South Korean popular culture as a negotiated response to cultural identity deconstructed and reconstructed in performance. The research methodology is to analyze a South Korean television reality show program on MBC Hangout with Yoo that represents various sub-characters performed by Jae-suk Yoo, a South Korean comedian and host. As for theoretical underpinning, this exploration joins work on Erving Goffman's (1959) notion of self-presentation and Chris Rojek's (2001) celebrity studies.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.13.2-13.2
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• 2005

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.61.1-61.1
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• 2005

• Journal of the KSME
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• v.31 no.7
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• pp.636-643
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• 1991

그 동안 투자가치를 기준으로 국내 가전 및 자동차산업 분야에서 고품질작업을 위한 로봇 시스 템(소형부품 조립과 스폿, 아크용접 및 실릴용 등)의 도입이 대기업을 중심으로 활발히 전개되어 왔으나, 90년대에 들어서면서 로봇 적용기술력의 향상과 로봇 시스템가격의 하락에 힘입어 열 악한 작업환경에서 작업인력을 대치할 수 있고, 다품종 소량생산에 적용할 다기능 및 지능로봇 시스템의 도입이 활발하게 검토되고 있다. 여기서는 이러한 제조업 분야의 자동화동향변화에 부응하여, 열악한 작업환경을 지닌 주물공장에서 3D 작업환경을 기피하는 작업자를 대신하고, 공장자동화의 한 셀(CELL)로서 연계자동화에 적용할 수 있는 주물소재의 가스절단 로봇 시스템 및 다버링 로봇 시스템에 대하여 당사의 개발적용 사례를 소개하고자 한다.