• Geophysics and Geophysical Exploration
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• v.5 no.4
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• pp.257-261
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• 2002

We have carried out integrated research including field survey and numerical modeling to appraise the applicability of SP method to the leakage problems of irrigation facilities. The leakage pattern of the dike studied here can be classified into the three categories: leakage through the abutment, leakage by piping through dike, and leakage due to the composite effects of landslide and distortion of the dike structure. for the numerical modeling to interpret quantitatively SP survey results acquired at dike, we have modified the computer code proposed by Sill (1983) to apply to the leakage problems. The numerical studies match the characteristic patterns of SP anomalies according to the leakage types and appear to be very useful to interpret the leakage zone and path. The SP monitoring results were also well coincided with tidal variations observed at every embankment so we found the SP method is quite effective not only to detect the leakage zone but also to determine the leakage trend. The numerical modeling results also reproduced the SP anomalies due to seawater leakage in the embankment.

• Tunnel and Underground Space
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• v.21 no.3
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• pp.216-224
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• 2011

In this study, Class II behavior of rock failure process under uniaxial and biaxial compression has been numerically simulated using bonded particle model. Class II behavior of rock was simulated by radial strain controlled uniaxial and biaxial compression tests using a suggested method of ISRM. Micro-parameters used in the simulation were determined based on the laboratory uniaxial compression tests carried out at ${\"{A}}sp{\"{o}}$ Hard Rock Laboratory, Sweden. Class II behavior of ${\"{A}}sp{\"{o}}$ rock was effectively simulated using newly proposed numerical technique in this study, and the results of numerical simulations show good similarity with the complete stress-strain curves for Class II behavior obtained from the laboratory tests.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.940-942
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• 2008

분산되어 있는 스토리지 자원을 하나의 클러스터로 구성하여 분산 파일 시스템으로 구성하고자 하는 경우, 기존의 네트워크 파일 시스템만을 이용하기에는 여러 가지 제약이 존재한다. 특히 Parallel Striped Access는 IO데이터를 스토리지에 나누어 분산시키고 클라이언트가 직접 접근하는 방식으로 병렬 파일 시스템과 같은 HPC 용 특수 파일 시스템에서는 이미 사용되는 기법이나, 일반적인 시스템을 대상으로 한 표준안의 부재가 제약이 된다. pNFS(Parallel NFS)는 이러한 문제를 해결하기 위해서 제시되는 새로운 NFS 기술이다. 본 연구에서는 pNFS의 연구 동향과 더불어 소규모 클러스터 시스템에서 나타나는 성능적 특징을 조사하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.4
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• pp.248-255
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• 2003

This paper presents a fingerprint recognition algorithm using cross-correlation function. This algorithm consists of minutiae extraction, minutiae alignment and minutiae matching, where we propose a new minutiae alignment method. In our alignment method, the rotation angle between two fingerprints is obtained by using cross-correlation function of the minutia directions, thereafter the displacement is obtained from the rotated fingerprint. This alignment method is capable of finding rotation angle and displacement of two fingerprints without resorting to exhaustive search. Our fingerprint recognition algorithm has been tested on fingerprint images captured with inkless scanner. The experiment results show that 17.299% false rejection ratio(FRR) at 2.086% false acceptance ratio(FAR).

• Korean Journal of Acupuncture
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• v.28 no.2
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• pp.1-11
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• 2011

Objectives : The aim of this study was to examine the effect acupuncture by needle manipulation at acupoints, SP3 HT7, on the blood pressure and renin and atrial natriuretic peptide(ANP) in plasma, cardiac hypertrophy in hypertensive rats induced by two kidney one clip (2K1C). Materials and Methods : The experiments were performed on twenty-five Sprague Dawley rats, 2K1C hypertension model was prepared by constricting the left renal artery with a sliver clip. Animals were divided into five groups, control, AC-1a and AC-2a(acupuncture at SP3 HT7 bilaterally and the needle was twirled and rotated forward with the thumb and forefinger of the right hand 6 times), AC-3a(acupuncture at SP3 HT7 bilaterally and the needle was inserted in the opposite direction(body direction) as the channel runs), AC-4a(acupuncture at SP3 HT7 bilaterally and the needle was inserted in the opposite direction(body direction) as the channel runs and the needle was twirled and rotated forward with the forefinger of the right hand 6 times). The treatments were started on the 4 week after inducing 2K1C, and they were performed two times a week for 3 weeks in rats. Results : The results are that The blood pressure was significantly decreased at 4 times in Acu-1a, The cardiac hypertrophy was significantly decrease in Acu-2a and Acu-3a. The activity of plasma renin was decreased in all groups without control and Acu-1a, and that of plasma ANP was decrease in Acu-2a and Acu-3a than control group. Conclusions : These results suggest that acupuncture on SP3 HT7 mostly cause significant changes on controlling renal hypertension induced by 2K1C in the rats.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.7
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• pp.167-176
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• 2019

Recently, as the types of services that can be enjoyed in mobile telecommunication networks such as social networks and video streaming are increasing, mobile users(MUs) can access mobile contents easily by consuming mobile data. However, under a mobile telecommunication environment, MUs have to pay a high data fee to a network service provider(SP) in order to enjoy contents. The 'data sponsor' technique, introduced as a way to solve this problem, has attracted attention as a breakthrough method for enhancing contents accessibility of MUs. In this paper, we propose an algorithm that determines the optimal discount rate through the Stackelberg game in the data sponsor environment. We also propose an algorithm to design edge caching, which caches highly popular content for MUs on edge server, through many-to-many matching game. Simulation results clearly indicate that the profit for CP's content consumption is improved by about 6~11%, and the profit of CP according to the ratio of edge caching is improved by about 12% than the other existing schemes under data sponsor environment.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.40-51
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• 2011

The key issues of recommendation systems provide the contents satisfying the interests of users for the huge amounts of contents over internet. The existing recommendation system use the algorithms considering the users' profiles and context information to enhance the exactness of a recommendation. However, the existing recommendation system can't satisfy the requirements of service providers because the business models of service providers is not considered. In this paper, we propose the mobile recommendation system using the composite contexts and the recommendation weights applying the business model of service providers. The proposed system retrieves the contents of the contents providers using composite context information and apply the recommendation weights to recommend the suitable contents for the business models of service providers. Therefore, we provide the contents satisfying the consumption value of users and the business models of service providers to mobile users.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.377-385
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• 2014

In this study, a wastewater treatment system for hypersaline wastewater utilizing the Hypersaline Wastewater Treatment Community (HWTC) has been developed. The hypersaline wastewater treatment efficiency and microbial community of the HWTC were investigated. The average removal efficiencies of chemical oxygen demand were 84% in an HRT of 2.5 days. Microbial community analysis, by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene fragments and 16S rRNA gene clone library, revealed community diversity. The 16S rRNA gene analysis of dominant microbial bacteria in 4% hypersaline wastewater confirmed the presence of Halomonas sp. and Paenibacillus sp. Phylogenetic analysis suggested that the taxonomic affiliation of the dominant species in the HWTC was ${\gamma}$-proteobacteria and firmicutes. These results indicate the possibility that an appropriate hypersaline wastewater treatment system can be designed using acclimated sludge with a halophilic community.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.3
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• pp.449-457
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• 2017

In this paper, we analyze the security and performance of the Quantis Quantum random number generator in terms of cryptography through experiments. The Quantis' post-processing is designed to output full-entropy via bit-matrix-vector multiplication based on mathematical background, and we used the min-entropy estimating test of NIST SP 800-90B so as to verify whether the output is full-entropy. Quantis minimizes the effect on the random bit rate by using an optimization technique for bit-matrix-vector multiplication, and compared the performance to conditioning functions of NIST SP 800-90B by measuring the random bit rate. Also, we have distinguished what is in Quantis' post-processing to the standard model of NIST in USA and BSI in Germany, and in case of applying Quantis to cryptographic systems in accordance with the CMVP standard, it is recommended to use the output of Quantis as the seed of the approved DRBG.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.347-362
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• 2020

Iron (hydro)oxides in aqueous environments are primarily formed due to mining activities, and they are known to be typical colloidal particles disturbing surrounding environments. Among them, hematites are widespread in surface environments, and their behavior is controlled by diverse factors in aqueous environments. This study was conducted to elucidate the effect of environmental factors, such as ionic composition and strength, pH, and natural organic matter (NOM) on the behavior of colloidal hematite particles. In particular, two analytical methods, such as dynamic light scattering (DLS) and single-particle ICP-MS (spICP-MS), were compared to quantify and characterize the behavior of colloidal hematites. According to the variation of ionic composition and strength, the aggregation/dispersion characteristics of the hematite particles were affected as a result of the change in the thickness of the diffuse double layer as well as the total force of electrostatic repulsion and van der Walls attraction. Besides, the more dispersed the particles were, the farther away the aqueous pH was from their point of zero charge (PZC). The results indicate that the electrostatic and steric (structural) stabilization of the particles was enhanced by the functional groups of the natural organic matter, such as carboxyl and phenolic, as the NOM coated the surface of colloidal hematite particles in aqueous environments. Furthermore, such coating effects seemed to increase with decreasing molar mass of NOM. On the contrary, these stabilization (dispersion) effects of NOM were much more diminished by divalent cations such as Ca²⁺ than monovalent ones (Na⁺), and it could be attributed to the fact that the former acted as bridges much more strongly between the NOM-coated hematite particles than the latter because of the relatively larger ionic potential of the former. Consequently, it was quantitatively confirmed that the behavior of colloidal hematites in aqueous environments was significantly affected by diverse factors, such as ionic composition and strength, pH, and NOM. Among them, the NOM seemed to be the primary and dominant one controlling the behavior of hematite colloids. Meanwhile, the results of the comparative study on DLS and spICPMS suggest that the analyses combining both methods are likely to improve the effectiveness on the quantitative characterization of colloidal behavior in aqueous environments because they showed different strengths: the main advantage of the DLS method is the speed and ease of the operation, while the outstanding merit of the spICP-MS are to consider the shape of particles and the type of aggregation.