• Structural Engineering and Mechanics
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• v.75 no.3
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• pp.401-414
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• 2020

Unlike the existing truss models for shear and torsion analysis, in this study, the torsional capacities of reinforced concrete (RC) members were estimated by introducing multi-potential capacity criteria that considered the aggregate interlock, concrete crushing, and spalling of concrete cover. The smeared truss model based on the fixed-angle theory was utilized to obtain the torsional behavior of reinforced concrete member, and the multi-potential capacity criteria were then applied to draw the capacity of the member. In addition, to avoid any iterative calculation in the existing torsional behavior model, a simple strength model was suggested that considers key variables, such as the effective thickness of torsional member, principal stress angle, and strain effect that reduces the resistance of concrete due to large longitudinal tensile strain. The proposed multi-potential capacity concept and the simple strength model were verified by comparing with test results collected from the literature. The study found that the multi-potential capacity could estimate in a rational manner not only the torsional strength but also the failure mode of RC members subjected to torsional moment, by reflecting the reinforcing index in both transverse and longitudinal directions, as well as the sectional and material properties of RC members.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1596-1600
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• 2010

Surface functionalization of multi-walled carbon nanotubes (MWNTs) was carried out by means of acid treatment. The presence of oxygen functional groups on the surface of acid-treated MWNTs was confirmed with the aid of Fourier transform infrared spectroscopy and X-ray spectroscopy. In addition, carboxylic groups generally formed on the surface of acid-treated MWNTs, and the dispersion was increased by the duration of the acid treatment. The zeta-potential indicated the surface charge transfer and the dispersion of MWMTs. Morphological characteristics of acid-treated MWNTs were also observed using a transmission electron microscopy, X-ray diffraction, and Raman analysis, which was revealed the significantly unchanged morphologies of MWNTs by acid treatment. The hydrogen adsorption capacity of the MWNTs was evaluated by means of adsorption isotherms at 77 K/1 atm. The hydrogen storage capacity was dependent upon the acid treatment conditions and the formation of oxygen functional groups on the MWNT surfaces. The latter have an important effect on the hydrogen storage capacity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.4
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• pp.651-669
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• 2013

In this paper, we study a novel routing algorithm based on load balancing for multi-channel wireless mesh networks. In order to increase the network capacity and reduce the interference of transmission streams and the communication delay, on the basis of weighted cumulative expected transmission time (WCETT) routing metric this paper proposes an improved routing metric based on load balancing and channel interference (LBI_WCETT), which considers the channel interference, channel diversity, link load and the latency brought by channel switching. Meanwhile, in order to utilize the multi-channel strategy efficiently in wireless mesh networks, a new channel allocation algorithm is proposed. This channel allocation algorithm utilizes the conflict graph model and considers the initial link load estimation and the potential interference of the link to assign a channel for each link in the wireless mesh network. It also utilizes the channel utilization percentage of the virtual link in its interference range as the channel selection standard. Simulation results show that the LBI_WCETT routing metric can help increase the network capacity effectively, reduce the average end to end delay, and improve the network performance.

• Journal of the Korean Society of Safety
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• v.34 no.5
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• pp.159-166
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• 2019

The seismic PSA is to probabilistically estimate the potential damage that a large earthquake will cause to a nuclear power plant. It integrates the probabilistic seismic hazard analysis, seismic fragility analysis, and system analysis and is utilized to identify seismic vulnerability and improve seismic capacity of nuclear power plants. Recently, the seismic risk of domestic multi-unit nuclear power plant sites has been evaluated after the Great East Japan Earthquake and Gyeongju Earthquake in Korea. However, while the currently available methods for system analysis can derive basic required results of seismic PSA, they do not provide the detailed results required for the efficient improvement of seismic capacity. Therefore, for in-depth seismic risk evaluation, improved system analysis method for seismic PSA has become necessary. This study develops a system analysis method that is not only suitable for multi-unit seismic PSA but also provides risk information for the seismic capacity improvements. It will also contribute to the enhancement of the safety of nuclear power plants by identifying the seismic vulnerability using the detailed results of seismic PSA. In addition, this system analysis method can be applied to other external event PSAs, such as fire PSA and tsunami PSA, which require similar analysis.

• Knowledge Management Research
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• v.20 no.1
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• pp.133-153
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• 2019

Due to the uncertainty of dynamic business environment, modern organizations have been giving attention to dynamic capabilities beyond traditional notion of core competence. Among them, absorptive capacity and boundary-spanning activity are considered the most important. The former refers to activities regarding acquisition, assimilation, transformation and exploitation of internal and external knowledge. The latter is composed of boundary-loosening and boundary-tightening activities to detect internal or external information and then to preserve, protect, or acquire resources. Thus, both have achieved wide recognition as a potential source of change and innovation. This study investigated the cross-level relation between boundary-spanning leadership at team level and absorptive capacity at individual level. We also explored self-efficacy and extra-role behavior that can affect employees' absorptive capacity. To test multi-level analysis, the survey data were collected from 862 members in 137 teams of different firms. Results revealed that boundary-spanning leadership had the positive cross-level impact on absorptive capacity in the team context. Moreover, absorptive capacity was positively associated with self-efficacy and extra-role behavior at individual level. Based on these findings, we provided theoretical and practical implications to address rapidly changing environments and discussed limitations of this paper for further research.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.1067-1086
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• 2023

With rapid advances in meat science in recent decades, changes in meat quality during the pre-slaughter phase of muscle growth and the post-slaughter process from muscle to meat have been investigated. Commonly used techniques have evolved from early physicochemical indicators such as meat color, tenderness, water holding capacity, flavor, and pH to various omic tools such as genomics, transcriptomics, proteomics, and metabolomics to explore fundamental molecular mechanisms and screen biomarkers related to meat quality and taste characteristics. This review highlights the application of omics and integrated multi-omics in meat quality and taste characteristics studies. It also discusses challenges and future perspectives of multi-omics technology to improve meat quality and taste. Consequently, multi-omics techniques can elucidate the molecular mechanisms responsible for changes of meat quality at transcriptome, proteome, and metabolome levels. In addition, the application of multi-omics technology has great potential for exploring and identifying biomarkers for meat quality and quality control that can make it easier to optimize production processes in the meat industry.

• Transactions of Materials Processing
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• v.24 no.3
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• pp.187-193
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• 2015

The objective of the current study is to determine cross-sectional profile of intermediate dies in order to improve the plastic strain homogeneity which directly affects not only the dimensional accuracy but also the mechanical properties of final product by redesigning the intermediate dies using the conventional electric field analysis (EFA) method. Initially, the multi-pass shape wire drawing was designed by using the equivalent potential lines from EFA. The area reduction ratio was calculated from the number of passes in multi-pass shape wire drawing but constrained by the capacity of the drawing machine and the drawing force. In order to compensate for a concentration of strain in a region of the cross section of the wire, the process for multi pass wire drawing from initial round material to an intermediate die was redesigned again using the electric field analysis. Both drawing process designs were simulated by the finite element method in which the strain distribution and standard deviation plastic strain of the cross section of drawn wires were examined.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.3
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• pp.48-54
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• 1998

Korea becomes one of the countries which suffer from water shortage. It is expected that its water shortage in the early 2000's will be more than 10% of the annual demand. The shortage problem is more serious in the coastal areas where many industry complex locate. To solve the shortage problem, seawater desalination gets more attention as an alternative water supply source since Korea is surrounded by sea on its three sides. For potential application of seawater desalination in Korea, an economic analysis was conducted using cost data for the plants in the Middle Ease areas, The United states and others. The study is to provide a basis for the government to establish a strategy for promoting seawater desalination in Korea. It is discussed that the Reverse Osmosis (RO) process gets cheaper over times than the thermal processes of Multi-stage Flash Distillation (MSF) and Multi Effect Distillation (ME), especially in case where the capacity is less than about 50,000 ton/day. The unit cost of RO seawater is analyzed about US$1.35/ton in 1990 price. Since the Desalination plant can be operated regardless of weather conditions, industries in Korea's coastal areas which suffer from frequent droughts and water shortages are recommended to look into this option with more attention.

• Journal of the Semiconductor & Display Technology
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• v.22 no.4
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• pp.53-58
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• 2023

The storage capacity of 3D-NAND flash memory has been enhanced by the multi-layer dielectrics. The deposition process has become more challenging due to the tight process margin and the demand for accurate process control. To reduce product costs and ensure successful processes, process diagnosis techniques incorporating artificial intelligence (AI) have been adopted in semiconductor manufacturing. Recently there is a growing interest in process diagnosis, and numerous studies have been conducted in this field. For higher model accuracy, various process and sensor data are required, such as optical emission spectroscopy (OES), quadrupole mass spectrometer (QMS), and equipment control state. Among them, OES is usually used for plasma diagnostic. However, OES data can be distorted by viewport contamination, leading to misunderstandings in plasma diagnosis. This issue is particularly emphasized in multi-dielectric deposition processes, such as oxide and nitride (ON) stack. Thus, it is crucial to understand the potential misunderstandings related to OES data distortion due to viewport contamination. This paper explores the potential for misunderstanding OES data due to data distortion in the ON stack process. It suggests the possibility of excessively evaluating process drift through comparisons with a QMS. This understanding can be utilized to develop diagnostic models and identify the effects of viewport contamination in ON stack processes.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.2
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• pp.107-116
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• 2016

Density of Phase-Change Memory (PCM) devices has been doubled through the employment of multi-level cell (MLC) technology. However, this doubled-capacity comes in the expense of severe performance degradation, as compared to the conventional single-level cell (SLC) PCM. This negative effect on the performance of the MLC PCM detracts from the potential benefits of the MLC PCM. This paper introduces an efficient way of minimizing the performance degradation while maximizing the capacity benefits of the MLC PCM. To this end, we propose a location-aware hybrid management of SLC and MLC in compressed PCM main memory systems. Our trace-driven simulations using real application workloads demonstrate that the proposed technique enhances the performance and energy consumption by 45.1% and 46.5%, respectively, on the average, over the conventional technique that only uses a MLC PCM.