• Journal of Advanced Navigation Technology
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• v.23 no.2
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• pp.207-213
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• 2019

Recently, the importance for internet of things (IoT) security has increased enormously and hardware-based compact chips are needed in IoT communication industries. In this paper, we propose low-complexity crypto-processor that unifies advanced encryption standard (AES), academy, research, institute, agency (ARIA), and CLEFIA protocols into one combined design. In the proposed crypto-processor, encryption and decryption processes are shared, and 128-bit round key generation process is combined. Moreover, the shared design has been minimized to be adapted in generic IoT devices and systems including lightweight IoT devices. The proposed crypto-processor was implemented in Verilog hardware description language (HDL) and synthesized to gate level circuit in 65nm CMOS process, which results in 11,080 gate counts. This demonstrates roughly 42% better than the aggregates of three algorithm implementations in the aspect of gate counts.

• Geomechanics and Engineering
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• v.17 no.5
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• pp.485-496
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• 2019

Sealing of leakage in waterfront or water-retaining structures is one of the major issues in geotechnical engineering practices. With demands for biological methods as sustainable ground improvement techniques, bioclogging, defined as the reduction in hydraulic conductivity of soils caused by microbial activities, has been considered as an alternative to the chemical grout techniques for its economic advantages and eco-friendliness of microbial by-products. This study investigated the feasibility of bioaugmentation and biostimulation methods to induce fermentation-based bioclogging effect in coarse sands. In the bioaugmentation experiments, effects of various parameters and conditions, including grain size, pH, and biogenic gas generation, on hydraulic conductivity reduction were examined through a series of column experiments while Leuconostoc mesenteroides, which produce an insoluble biopolymer called dextran, was used as the model bacteria. The column test results demonstrate that the accumulation of bacterial biopolymer can readily reduce the hydraulic conductivity by three-to-four orders of magnitudes or by 99.9-99.99% in well-controlled environments. In the biostimulation experiments, two inoculums of indigenous soil bacteria sampled from waterfront embankments were prepared and their bioclogging efficiency was examined. With one inoculum containing species capable of fermentation and biopolymer production, the hydraulic conductivity reduction by two orders of magnitude was achieved, however, no clogging was found with the other inoculum. This implies that presence of indigenous species capable of biopolymer production and their population, if any, play a key role in causing bioclogging, because of competition with other indigenous bacteria. The presented results provide fundamental insights into the bacterial biopolymer formation mechanism, its effect on soil permeability, and potential of engineering bacterial clogging in subsurface.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2496-2512
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• 2021

The requirements for powerful computing capability, high capacity, low latency and low energy consumption of emerging services, pose severe challenges to the fifth-generation (5G) network. As a promising paradigm, mobile edge networks can provide services in proximity to users by deploying computing components and cache at the edge, which can effectively decrease service delay. However, the coexistence of heterogeneous services and the sharing of limited resources lead to the competition between various services for multiple resources. This paper considers two typical heterogeneous services: computing services and content delivery services, in order to properly configure resources, it is crucial to develop an effective offloading and caching strategies. Considering the high energy consumption of 5G base stations, this paper considers the hybrid energy supply model of traditional power grid and green energy. Therefore, it is necessary to design a reasonable association mechanism which can allocate more service load to base stations rich in green energy to improve the utilization of green energy. This paper formed the joint optimization problem of computing offloading, caching and resource allocation for heterogeneous services with the objective of minimizing the on-grid power consumption under the constraints of limited resources and QoS guarantee. Since the joint optimization problem is a mixed integer nonlinear programming problem that is impossible to solve, this paper uses deep reinforcement learning method to learn the optimal strategy through a lot of training. Extensive simulation experiments show that compared with other schemes, the proposed scheme can allocate resources to heterogeneous service according to the green energy distribution which can effectively reduce the traditional energy consumption.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.2
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• pp.59-64
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• 2021

System-in-package (SIP) technology using heterogeneous integration is becoming the key of next-generation semiconductor packaging technology, and the development of low temperature Cu bonding is very important for high-performance and fine-pitch SIP interconnects. In this study the low temperature Cu bonding and the anti-oxidation effect of copper using porous Ag nanolayer were investigated. It has been found that Cu diffuses into Ag faster than Ag diffuses into Cu at the temperatures from 100℃ to 200℃, indicating that solid state diffusion bonding of copper is possible at low temperatures. Cu bonding using Ag nanolayer was carried out at 200℃, and the shear strength after bonding was measured to be 23.27 MPa.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.566-574
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• 2011

Coal gasifier is a key component for achieving high efficiency in integrated gasification combined cycle and indirect coal liquefaction. Although there have been several successful coal gasifiers that were commercially proven, many different design configurations are still possible for a simple and reliable gasifier operation. Four different gasifier design concepts of dry-feeding were compared in terms of residence time, exit syngas temperature and syngas composition. First, cold-flow simulation was applied to pre-select the configuration concepts, and the hot-flow simulation including chemical reactions was performed to compare the concepts at more actual gasifier operating conditions. There are many limitations in applying CFD method in gasifier design, particularly in estimating slag behavior and slag-tap design. However, the CFD analysis proved to be useful in comparing the widely different gasifier design concepts as a pre-selection tool.

• Journal of English Language & Literature
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• v.58 no.2
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• pp.279-304
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• 2012

Since the publication of Foucault's Discipline and Punish, theatricality has become one of the key concepts in New Historicism. By defining theatricality as the most definitive feature of early modern society and culture, New Historicists have promoted the idea that theatrical practices in every day life were eventually replaced by textual practices as the western society started to undergo modernization with the advent of print culture and technologies. This paper questions this linear model of English literature, the shift of literary practices from theatricality to textuality in the event of modernization, by closely looking at the ways in which newsbooks and playlets during the English civil wars appealed to their target readers. The early print-based literary commodities during the English civil war (i.e. newsbooks and playlets) were able to win the attention of their audience not by breaking away from theatrical energy and creativity but instead by embracing and taking advantage of them through the use of dramatic conventions, dialogues, and many others. The newsbooks and the playlets during the time, however, did not simply replicate the dramatic forms and experiences of the previous generation. Instead, as the case study of Craftie Cromwell exemplifies, they went further to produce a different mode of theatricality by reshaping everyday lives into serialized drama, whose resolution is always already delayed and postponed into the ever-receding future. In conclusion, the study of the newsbook and playlets during the civil wars suggests that the textuality of modern times, materialized in print forms, have been co-evolved with the development of new theatricality, whose contents and forms are susceptible to the changes of everyday reality.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.4
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• pp.67-75
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• 2001

3GPP proposed f8 and f9 algorithms based on the block cipher KASUMI to provide the data confidentiality and integrity over a radio access link for IMT-2000(W-CDMA). Also 3GPP proposed Milenage algorithm based on the block cipher Rijndael to provide an example set for 3GPP authentication and key generation functions. In order to analyze the security of 3GPP algorithms, we must go ahead an analysis of security of KASUMI and Rijndael. Since S-box is an important point of security of block cipher, in this paper we analyze the S-boxes of KASUMI and Rijndael and compare the S-boxes of KASUMI with the S-box of Rijndael. Although KASUMI S9-box is bad for AC and SAC, we find that AC of KASUMI FI function containing S7-box and S9-box is equal to AC of Rijndael S-box and SAC of KASUMI FI function is better than SAC of Rijndael S-box.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.1
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• pp.155-167
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• 2012

Cloud computing service is a next generation IT service which has pay-per-use billing model and supports elastically provisioning IT infra according to user demand. However it has many potential threats originating from outsourcing/supporting service structure that customers 'outsource' their own data and provider 'supports' infra, platform, application services, the complexity of applied technology, resource sharing and compliance with a law, etc. In activation of Cloud service, we need objective assessment standard to ensure safety and reliability which is one of the biggest obstacles to adopt cloud service. So far information security management system has been used as a security standard for a security management and IT operation within an organization. As for Cloud computing service it needs new security management and assessment different from those of the existing in-house IT environment. In this paper, to make a Information Security Management System considering cloud characteristics key components from threat management system are drawn and all control domain of existing information security management system as a control components are included. Especially we designed service security management to support service usage in an on-line self service environment and service contract and business status.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.1
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• pp.264-284
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• 2021

As the next-generation network architecture, software-defined networking (SDN) has great potential. But how to forward data packets safely is a big challenge today. In SDN, packets are transferred according to flow rules which are made and delivered by the controller. Once flow rules are modified, the packets might be redirected or dropped. According to related research, we believe that the key to forward data flows safely is keeping the consistency of flow rules. However, existing solutions place little emphasis on the safety of flow rules. After summarizing the shortcomings of the existing solutions, we propose FRChain to ensure the security of SDN data forwarding. FRChain is a novel scheme that uses blockchain to secure flow rules in SDN and to detect compromised nodes in the network when the proportion of malicious nodes is less than one-third. The scheme places the flow strategies into blockchain in form of transactions. Once an unmatched flow rule is detected, the system will issue the problem by initiating a vote and possible attacks will be deduced based on the results. To simulate the scheme, we utilize BigchainDB, which has good performance in data processing, to handle transactions. The experimental results show that the scheme is feasible, and the additional overhead for network performance and system performance is less than similar solutions. Overall, FRChain can detect suspicious behaviors and deduce malicious nodes to keep the consistency of flow rules in SDN.

• Wind and Structures
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• v.32 no.1
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• pp.55-69
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• 2021

Ultrapure ferritic stainless steel provides a new generation of long-span metal roof systems with continuous welding technology, which exhibits many unknown behaviors during wind excitation. This study focuses on the wind-resistant capacity of a new continuous welding stainless steel roof (CWSSR) system. Full-scale testing on the welding joints and the CWSSR system is performed under uniaxial tension and static ultimate wind uplift loadings, respectively. A finite element model is developed with mesh refinement optimization and is further validated with the testing results, which provides a reliable way of investigating the parameter effect on the wind-induced structural responses, namely, the width and thickness of the roof sheeting and welding height. Research results show that the CWSSR system has predominant wind-resistant performance and can bear an ultimate wind uplift loading of 10.4 kPa without observable failures. The welding joints achieve equivalent mechanical behaviors as those of base material is produced with the current of 65 A. Independent structural responses can be found for the roof sheeting of the CWSSR system, and the maximum displacement appears at the middle of the roof sheeting, while the maximum stress appears at the connection supports between the roof sheeting with a significant stress concentration effect. The responses of the CWSSR system are greatly influenced by the width and thickness of the roof sheeting but are less influenced by the welding height.