• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.476-484
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• 2018

The high capacity audio watermarking algorithms are facing a main challenge in satisfying the robustness against attacks especially on de-synchronization attacks. In this paper, a robust and a high capacity algorithm is proposed using segment selection, Stationary Wavelet Transform (SWT) and the Quantization Index Modulation (QIM) techniques along with new synchronization mechanism. The proposed algorithm provides enhanced trade-off between robustness, imperceptibility, and capacity. The achieved watermarking improves the reliability of the available watermarking methods and shows high robustness towards signal processing (manipulating) attacks especially the de-synchronization attacks such as cropping, jittering, and zero inserting attacks. For imperceptibility evaluation, high signal to noise ratio values of above 22 dB has been achieved. Also subjective test with volunteer listeners shows that the proposed method has high imperceptibility with Subjective Difference Grade (SDG) of 4.76. Meanwhile, high rational capacity up to 176.4 bps is also achieved.

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.933-938
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• 2006

Different multimedia services over networks not only require different amounts of bandwidth but also have different Qualify of Service (QoS) requirements. For example, QoS guarantees for higher priority calls is an important issue in multimedia communication networks. In this paper, we develop an adaptive bandwidth management algorithm, which is able to provide QoS guarantees for higher priority calls while accommodating as many heterogeneous multimedia call connections as possible. Our scheme, based on reservation and bandwidth adaptation, manages bandwidth based on real time estimates of current network conditions. Simulation results indicate the superior performance of our scheme providing excellent trade off between contradictory requirements.

• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.504-511
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• 2007

Built-out issue of copper processing appearing recently in the Paldang watershed is a critical problem to deteriorate the basic framework of national water management policy as well as to be simply a copper-related problem. Up to now, Korea government has invested hard and relevant upstream areas have been victimized readily in a variety of field to comply its goal of 'Safe Water Supply'. Because of the reason, the desirable water quality level of the Paldang watershed has been maintained regardless of its dense population. Paldang drinking water management policy is based on residents' understanding which is considered as a 'social capital'. The issue raised in the aspect of water quality management policy should be reviewed on the basis of the 'social capital' concept. One regarding semiconductor industry as a potential industry to export many products in 10 years insists that the industry not be a simple private business but be a prominent part for national competitiveness. There is no doubt about this opinion. However, a nation should support environmental right-to-life of its people prior to any other tasks. In other words, it is really risky to give up people's right due to economic benefits. Therefore, it should not happen to trade 'life', the dignity of man, with national competitiveness which is likely to be preferred in these days. In addition, coherent policy not to destroy 'social capital' promoting Paldang drinking water resource management policy should be maintained.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.8
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• pp.3918-3934
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• 2017

This paper presents a viewport resolution scaling technique to reduce power consumption in mobile graphic processing units (GPUs). This technique controls the rendering resolution of applications in proportion to the resolution factor. In the mobile environment, it is essential to find an effective resolution factor to achieve low power consumption because both the resolution and power consumption of a GPU are in mutual trade-off. This paper presents a resolution factor that can minimize image quality degradation and gain power reduction. For this purpose, software and hardware viewport resolution scaling techniques are applied in the Android environment. Then, the correlation between image quality and power consumption is analyzed according to the resolution factor by conducting a benchmark analysis in the real commercial environment. Experimental results show that the power consumption decreased by 36.96% on average by the hardware viewport resolution scaling technique.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.09a
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• pp.219-225
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• 2002

This paper presents a novel "bumpless flip chip package"for cost! performance driven devices. Using the conventional electroplating and etching processes, this package enables the production of fine pitch BGA up to 256 I/O with single layer routing. An array of circuitry down to $25-50{\mu}{\textrm}{m}$ line/space is fabricated to fan-in and fan-out of the bond pads without using bumps or substrate. Various types of joint methods can be applied to connect the fine trace and the bond pad directly. The resin-filled terminal provides excellent compliancy between package and the assembled board. More interestingly, the thin film routing is similar to wafer level packaging whereas the fan-out feature enables high lead count devices to be accommodated in the BGA format. Details of the design concepts and processing technology for this novel package are discussed. Trade offs to meet various cost or performance goals for selected applications are suggested. Finally, the importance of design integration early in the technology development cycle with die-level and system-level design teams is highlighted as critical to an optimal design for performance and cost.

• Journal of Korea Society of Digital Industry and Information Management
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• v.18 no.1
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• pp.11-24
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• 2022

Open Radio Access Network (O-RAN) standard has been proposed to separate the baseband signal processing unit from the Radio Frequency (RF) unit at base station system mainly for reducing the cost of base station systems through open-source interfaces between the two units. To satisfy the performance metrics in various scenarios, several fronthaul functional split options were presented by O-RAN. Amongst these options, the split option 7-2x is widely adopted in practical applications due to its excellent trade-off between the required bandwidth and RU overhead. In this paper, we present a hardware implementation of a base station system that is compliant with the Category B of O-RAN split option 7-2x. It consists of O-DU and O-RU implemented with a commercial off-the-shelf Digital Signal Processor and RF transceiver, respectively. The performance of the proposed base station system is evaluated in terms of Bit Error Rate and received signal power as well as the required fronthaul bandwidth. Through various experimental tests, we have observed that the proposed system reduces the fronthaul bandwidth nearly by 89.7% compared to the conventional system that dose not employ the O-RAN standard.

• Korean Journal of Materials Research
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• v.33 no.7
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• pp.309-314
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• 2023

This study aimed to address the limitations of traditional plasma nitriding methods by implementing a short-term plasma oxy-nitriding treatment on the surface of AISI 420 martensitic stainless steel. This treatment involved the sequential formation of nitride and oxide layers, to enhance surface hardness and corrosion resistance, respectively. The process resulted in the formation of a 20 ㎛-thick nitride layer and a 3 ㎛-thick oxide layer on the steel surface. Initially, the hardness increased by 2.2 times after nitriding, followed by a subsequent decrease of approximately 31 % after oxidation. While the nitriding process reduced corrosion resistance, the subsequent oxidation process led to the formation of a passive oxide film, effectively resolving this issue. The pitting corrosion of the oxide passive film started at 82.6 mVssc, providing better corrosion resistance characteristics than the nitride layer. Consequently, the trade-off between surface hardness and corrosion resistance in plasma oxy-nitrided AISI 420 martensitic stainless steel is anticipated to be recognized as an innovative and comprehensive surface treatment process for biomedical components.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.13-22
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• 2020

Reinforcement steel fixing is a skilled and manually intensive construction trade. Current practice for the quality assessment of reinforcement steel fixing is normally performed by fabricators and has high potential in having errors due to the tedious nature of the work. In order to overcome the current inspection limitation, this study presents an approach that provides visual assistance and inspection enhancement for inspectors to assess the dimensional layout of reinforcement steel fixing. To this end, this study aims to establish an end-to-end framework for rebar layout quality inspection using laser scanning and Augmented Reality (AR). The proposed framework is composed of three parts: (1) the laser-scanned rebar data processing; (2) the rebar inspection procedure integrating with AR; and (3) the checking and fixing the rebar layout through AR visualization. In order to investigate the feasibility of the proposed framework, a case study assessing the rebar layout of a lab-scaled formwork containing two rebar layers is conducted. The results of the case studies demonstrate that the proposed approach using laser scanning and AR has the potential to produce an intuitive and accurate quality assessment for the rebar layout.

• Asia pacific journal of information systems
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• v.34 no.2
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• pp.400-420
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• 2024

Nowadays, social media has evolved into a powerful networked ecosystem in which governments and citizens publicly debate economic and political issues. This holds true for the pros and cons of Indonesia's ore nickel export restriction to Europe, which we aim to investigate further in this paper. Using Twitter as a dependable channel for conducting sentiment analysis, we have gathered 7070 tweets data for further processing using two sentiment analysis approaches, namely Support Vector Machine (SVM) and Long Short Term Memory (LSTM). Model construction stage has shown that Bidirectional LSTM performed better than LSTM and SVM kernels, with accuracy of 91%. The LSTM comes second and The SVM Radial Basis Function comes third in terms of best model, with 88% and 83% accuracies, respectively. In terms of sentiments, most Indonesians believe that the nickel ore provision will have a positive impact on the mining industry in Indonesia. However, a small number of Indonesian citizens contradict this policy due to fears of a trade dispute that could potentially harm Indonesia's bilateral relations with the EU. Hence, this study contributes to the advancement of measuring public opinions through big data tools by identifying Bidirectional LSTM as the optimal model for the dataset.

• Land and Housing Review
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• v.5 no.1
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• pp.41-51
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• 2014

The amount of new apartment construction has been trending upward in 3~4% each year since 11% increase in 2002. Currently, in public apartment construction sites under separate delivery system for construction waste processing, the significant difference between estimated quantity for contract and actual amount frequently causes severe controversy among project participants. Many factors such as poor environmental management, inadequate contractual amount are assumed to influence the above problem, and the requirement to revise existing generation rates, the key criteria applied in estimating the quantities of waste, is increasing. Most of generation rates were established in early 2000's, and have difficulty in reflecting the changes from new materials and technologies accordingly. Therefore, this study aims to clarify the types of construction waste for each trade and the forecast method as preliminary work in order to develop more accurate generation rates for construction waste in new construction. To achieve this purpose, the architectural bills of quantities in ten apartment projects executed during 2010~2013 were collected, and the possible waste types and reasonable material loss ratio for each item from temporary works to owner-supplying material area were defined and compared through the workshops and interviews with the experts and on-site environmental managers. The results of this study will contribute to establishing the categories of construction waste for construction trades and proper generation rates by the indirect estimation method in new apartment construction in the follow-up study.