• 한국주거학회논문집
• /
• 제25권3호
• /
• pp.115-121
• /
• 2014

This paper draws the home into the stream of information and communications technology (ICT) development. Considering that homes and our home life are constantly affected by persistent change influenced by ICT, it is remarkable that ICT has been relatively neglected as an object of research in the field of housing studies. This study provides an overview of conceptual movements in ICT/home relationships and their design and social impact through a critical discourse analysis. The conceptual movements must be considered by professionals in the field of housing and built environment to stay attuned to changes in the 21st Century. Diverse debates took place in the discourse about ICT in relation to home. The stream of thought was started by futurists who saw the electronic cottage as a solution to the social problems caused by the separation of work and home life in industrial cities. ICT has now entered a new phase, with WiFi P2P networks and location-based social media that encourage sharable homes. Based on the analysis of the discourse on ICT and home, we drew from three issues related to the paradigm shifts in homes in the context of ICT development to provide future directions for housing studies: from space programming to time scheduling, from individual ownership to shared access, and from live+work dwelling to live+work+community.

• Journal of Communications and Networks
• /
• 제18권6호
• /
• pp.902-912
• /
• 2016

Recent advances in energy harvesting (EH) technology have motivated the adoption of rechargeable mobile devices for communications. In this paper, we consider a point-to-point (P2P) wireless communication system in which an EH transmitter with a non-ideal rechargeable battery is required to send a given fixed number of bits to the receiver before they expire according to a preset delay constraint. Due to the possible energy loss in the storage process, the harvest-use-and-store (HUS) architecture is adopted. We characterize the properties of the optimal solutions, for additive white Gaussian channels (AWGNs) and then block-fading channels, that maximize the energy efficiency (i.e., battery residual) subject to a given rate requirement. Interestingly, it is shown that the optimal solution has a water-filling interpretation with double thresholds and that both thresholds are monotonic. Based on this, we investigate the optimal double-threshold based allocation policy and devise an algorithm to achieve the solution. Numerical results are provided to validate the theoretical analysis and to compare the optimal solutions with existing schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제4권5호
• /
• pp.709-735
• /
• 2010

The reciprocal virtue of peer-to-peer networking has stimulated an explosion of peer population and service capacity, ensuring rapid content distribution in peer-to-peer networks. Critical issues such as peer churn, free riding, and skewed workload significantly affect performance results such as service agility, fairness, and resource utilization. To resolve these problems systematically, this study proposes a peer assignment scheme that supports fair peer-to-peer file sharing applications. The proposed scheme exploits the peer duality of both server-oriented peer capacity and client-oriented peer contribution. Accordingly, the system server can prioritize download requests and appropriately assign server peers to uploading file objects. Several functional extensions, including peer substitution and elimination, bandwidth adjustment, and distributed modification, help cope with subtle situations of service starvation and download blocking, and hence make the system design robust and amenable. Simulation results show this design is examined under both centralized and distributed peer-to-peer environments. Performance results confirm that the proposed mechanisms are simple but effective in maintaining service agility and fairness, without loss of overall service capacity in peer-to-peer files sharing systems.

• 공업화학
• /
• 제5권2호
• /
• pp.321-326
• /
• 1994

에테르기를 가진 수용성 포스파젠 고분자를 감마광선에 노출시켜 좋은 수분-팽윤도를 가진 친수성 겔을 만들었다. 이 친수성 겔들의 물리적 강도가 감마광선의 강도에 따라 조절될 수 있었다. 트립신과 수용성 포스파젠 고분자를 함께 감마광선에 쪼여 트립신을 겔의 망 사이로 고정시켰다. 고정된 트립신의 활성도는 N-${\alpha}$-benzoyl-1-arginine-p-nitroanilide와 반응시킨 후 분광학적인 방법으로 조사하였다. 고정된 트립신은 적어도 500시간 후에도 상당히 좋은 활성도 수율과 안정도를 가지고 있었음을 보여주었다.

• Journal of Information Processing Systems
• /
• 제16권4호
• /
• pp.935-958
• /
• 2020

The core value of finance is credit. It can be said that without credit, there can be no finance. The distributed structure of the blockchain and the low-cost trust-building mechanism based on mathematical algorithms provide a new solution and path for solving and optimizing related problems in the financial field. The blockchain technology is applied in the development of the financial industry through consensus mechanisms, smart contracts, and distributed networks. In this research, a comprehensive survey of the blockchain technology is proposed in the development of financial services including equity crowdfunding and credit investigations in inclusive finance, cross-border remittance, Internet financial payment, P2P lending, supply chains finance, and the application of blockchain in the field of anti-money laundering. This paper discusses the role of blockchain in solutions to different issues in the financial field. It also discusses the architectures in different financial service application scenarios from the perspective of the financial trust mechanism and the perspective of the technology and rule change of blockchain participation in financial innovation. Finally, the problems and challenges of blockchain in financial services are discussed, and corresponding solutions are proposed.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2006년도 학술발표회 논문집
• /
• pp.64-69
• /
• 2006

At starting point, 1D velocity models were inverted by using 430 events with P-wave 5147, S-wave 3729 from KIGAM, KMA, KEPRI, and KINS's seismic networks. A minimum 1D model shows that P-wave velocities are around $6.0{\pm}0.5\;km/s$ slowly increasing with depth between surface and 15 km. The velocities are about $6.4{\pm}0.2\;km/s$ below 15km to 35km. The earthquake data number for 3D tomography was 630 adding to previous 430 events with limitation of more than 6 station detection and relocation stability of location. The checkerboard test shows that only upper curst part from surface to 17 km have reliable resolution. The results of upper crust part present that the boundary of Gyeong-sang basin and Youngnam massif is mach well velocity variation pattern. The western part of the basin is shown as lower velocity and south-eastern part as higher. This is because that sedimentary rocks are widely located around western part of the basin and volcanic origin rocks are distributed around south-eastern part.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권1호
• /
• pp.133-151
• /
• 2019

In order to achieve faster content distribution speed and stronger fault tolerance, a P2P peer can connect to multiple peers in parallel and receive chunks of the data simultaneously. A critical issue in this environment is selecting a set of nodes participating in swarming sessions. Previous related researches only focus on performance metrics, such as downloading time or the round-trip time, but in this paper, we consider a new performance metric which is closely related to the network and propose a peer selection algorithm that produces the set of peers generating optimal worst link stress. We prove that the optimal algorithm is practicable and has the advantages with the experiments on PlanetLab. The algorithm optimizes the congestion level of the bottleneck link. It means the algorithm can maximize the affordable throughput. Second, the network load is well balanced. A balanced network improves the utilization of resources and leads to the fast content distribution. We also notice that if every client follows our algorithm in selecting peers, the probability is high that all sessions could benefit. We expect that the algorithm in this paper can be used complementary to existing methods to derive new and valuable insights in peer-to-peer networking.

• 한국환경과학회지
• /
• 제27권11호
• /
• pp.1073-1081
• /
• 2018

In this study, an operational data set was analysed by establishing a path model to figure out the actual cause-effect relationship of a wastewater treatment plant (WWTP); in particular, for the effluent concentrations of T-N and T-P. To develop the path models, data sets of operational records including effluent concentrations and operational factors were obtained from a field scale WWTP of $680,000m^3$ of treatment capacity. The models showed that the relationship networks with the correlation coefficients between variables for objective expressions indicated the strength of each relationship. The suggested path models were verified according to whether the analyzation results matched known theories well, but sophisticated minute theoric relationships could not be cropped out distinctly. This indicates that only a few paths with strong theoric casual relationships were represented as measured data due to the high non-linearity of the mechanism of the removal process in a biological wastewater treatment.

• 대한의용생체공학회:의공학회지
• /
• 제37권2호
• /
• pp.61-67
• /
• 2016

This paper presented a method for random forest based the arrhythmia classification using both heart rate (HR) and heart rate variability (HRV) features. We analyzed the MIT-BIH arrhythmia database which contains half-hour ECG recorded from 48 subjects. This study included not only the linear features but also non-linear features for the improvement of classification performance. We classified abnormal ECG using mean_NN (mean of heart rate), SD1/SD2 (geometrical feature of poincare HRV plot), SE (spectral entropy), pNN100 (percentage of a heart rate longer than 100 ms) affecting accurate classification among combined of linear and nonlinear features. We compared our proposed method with Neural Networks to evaluate the accuracy of the algorithm. When we used the features extracted from the HRV as an input variable for classifier, random forest used only the most contributed variable for classification unlike the neural networks. The characteristics of random forest enable the dimensionality reduction of the input variables, increase a efficiency of classifier and can be obtained faster, 11.1% higher accuracy than the neural networks.

• 충청수학회지
• /
• 제28권2호
• /
• pp.331-343
• /
• 2015

Invertible transformations over n-bit words are essential ingredients in many cryptographic constructions. When n is large such invertible transformations are usually represented as a composition of simpler operations such as linear functions, S-P networks, Feistel structures and T-functions. Among them we study T-functions which are probably invertible transformations and are very useful in stream ciphers. In this paper we study the number of single cycle T-functions satisfying some conditions and characterize single cycle T-functions on $(\mathbb{Z}_2)^n$ generated by some elements in $(\mathbb{Z}_2)^{n-1}$.