• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.5
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• pp.866-874
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• 2006

This paper proposes a new Dynamic Voltage Scaling(DVS) algorithm to achieve low-power scheduling of aperiodic hard real-time tasks. Aperiodic tasks schedulingcannot be applied to the conventional DVS algorithm and result in consuming energy more than periodic tasks because they have no period, non predictable worst case execution time, and release time. In this paper, we defined Virtual Periodic Task Set(VTS) which has constant period and worst case execution time, and released aperiodic tasks are assigned to this VTS. The period and worst case execution time of the virtual task can be obtained by calculating task utilization rate of both periodic and aperiodic tasks. The proposed DVS algorithm scales the frequency of both periodic and aperiodic tasks in VTS. Simulation results show that the energy consumption of the proposed algorithm is reduced by 11% over the conventional DVS algorithm for only periodic task.

• Journal of Magnetics
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• v.11 no.2
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• pp.61-65
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• 2006

The physical origin of complex dynamic domain configuration in nonequilibrium magnetic systems with mesoscopic length scales has been studied. An increasing complexity in the spatial feature of the evolution is found to accompany the increasing reversal speed, when a ferromagnetic element is driven by progressively faster switching fields applied antiparallel to the initial magnetization direction. As reversal rates approach the characteristic precession frequencies of spin fluctuations, the thermal energy can boost the magnetization into local configurations which are completely different from those experienced during quasistatic reversal. The sensitive dependence of the spatial pattern on switching speed can be understood in terms of a dynamic exchange interaction of thermally excited spins; the coherent modulation of the spins is strongly dependent on the rise time of switching pulses.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.311-315
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• 2007

Since the first phase of NGIS (National Geographic Information System) project was launched in 1988, various types and spatial database has been produced and updated. With recent developments in the information technology, the application of spatial data has increased in amount as well as in the coverage of the area of interest. There is a need for production and management of a nationwide single continuous digital map. This paper looks into three problems of map edge matching when dealing with such a task : 1) different scales of adjacent maps, 2) different time of capture between adjacent maps, and 3) different responsible organization where map matching has not been peformed along the boundary.

• ETRI Journal
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• v.22 no.4
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• pp.1-12
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• 2000

Designing a reliable multicast-based network that scales to the size of a multicast group member is difficult because of the diversity of user demands. The loss inferences of internal nodes by end-to-end measurements do not require the use of complete statistics because of the use of maximum likelihood estimation. These schemes are very efficient and the inferred value converges fast to its true value. In the theoretical analysis, internal delay estimation is possible but the analysis is very complex due to the continuity property of the delay. In this paper, we propose the use of a bottleneck location estimator. This can overcome the analytical difficulty of the delay estimation using the power spectrum of the packet interarrival time as the performance metric. Both theoretical analysis and simulation results show that the proposed scheme can be used for bottleneck location inference of internal links in scalable multicasting.

• Korean Journal of Plant Taxonomy
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• v.50 no.2
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• pp.227-231
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• 2020

While conducting a floristic study of Korean hepatics, we discovered two unrecorded species, which were collected from wind holes near the Donggang River, Korea. Mannia fragrans (Balb.) Frye & L. Clark and Mannia androgyna (L.) A. Evans are hereby reported for the first time in Korea. M. androgyna is characterized by pale grayish oil bodies in both the aerenchyma and basal tissue, and saccate spores with a conspicuous proximal disc. M. fragrans is characterized by a gynoecial segment with a whitish apical brush of scales, a commonly aromatic smell, and areolate spores with a conspicuous proximal disc. Two unrecorded species are described and illustrated based on Korean material.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.148-152
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• 2015

Three marine heterotrophic flagellates from intertidal sediments of Gwang-Am beach and Garorim Bay, Korea were identified as Neometanema parovale Lee and Patterson 2014, Stephanopogon pattersoni Lee et al. 2014 and Thaumatomastix sp. These species are reported taxonomically for the first time from Korea, and are described with illustrations and micrographs. Diagnostics of these species are as follows. Neometanema parovale (Euglenozoa): size in vivo, $10{\sim}23{\mu}m\;long$ with 22 pellicular strips, ingestion apparatus barely visible by light microscopy and two flagella pointed in different directions when moving. Stephanopogon pattersoni (Percolozoa): size in vivo, $20{\sim}33{\mu}m\;long$, with 6 ventral and 1 ventro-lateral ciliary rows, and three barbs. Thaumatomastix sp. (Cercozoa): size in vivo, $14{\sim}17{\mu}m$ with body scales and spines, and two flagella with one naked and one scaled.

• Journal of The Korean Astronomical Society
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• v.37 no.5
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• pp.483-491
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• 2004

Clusters of galaxies are storage rooms of cosmic rays. They confine the hadronic component of cosmic rays over cosmological time scales due to diffusion, and the electron component due to energy losses. Hadronic cosmic rays can be accelerated during the process of structure formation, because of the supersonic motion of gas in the potential wells created by dark matter. At the shock waves that result from this motion, charged particles can be energized through the first order Fermi process. After discussing the most important evidences for non-thermal phenomena in large scale structures, we describe in some detail the main issues related to the acceleration of particles at these shock waves, emphasizing the possible role of the dynamical backreaction of the accelerated particles on the plasmas involved.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.547-552
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• 1998

The small-scale models have been utilized for the prediction of inelastic behavior of reinforced concrete structures for a long time. The parameters that affect the similitude between the model and the prototype are various. Among them, the effect of bond between the model reinforcement and the model concrete is one of the most important factors. The study reported herein is addressed to verifying this similitude in bond behavior. Another topic is the similitude in shear. The selected scales are 1/1, 1/5, 1/10 and 1/12. Two prototype specimens and three models were tested in addition to the associated material tests. The test results are compared from the viewpoint of similitude.

• Korean Journal of Child Studies
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• v.20 no.3
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• pp.19-32
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• 1999

This study analyzed the relation of children's attachment security and mother-child interaction to children's peer interactions. The subjects were 51 preschoolers, 44 to 57 months of age and their mothers. Attachment was assessed using the Attachment Q-set (Waters, 1987), mother-child interactions at home were observed with the use of the Teaching Strategies Rating Scales (Erickson, Sroufe, Egeland, 1985), and peer interactions were observed during free play time, using the Holloway and Erickson(1988) categories. Pearson correlation and multiple regression showed that attachment security scores were negatively related to dependency toward peers. Mother's "structure and limit setting" and "respect for child's autonomy" were positively related to "helping with peers" and negatively to "asking for help" and "physical attack". The variables accounting for dependency toward peers were mother's hostility and attachment security.

• Journal of Families and Better Life
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• v.19 no.4
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• pp.69-83
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• 2001

The purpose of this study was to construct the new premarital relationship enrichment program and to examine the effects of it. Based on the review of the previous research and program, this program was composed. It included the realistic expectations of marriage and sex, understanding of themselves and accepting differences, role expectations and intimacy in the relationship, communication and conflict resolution skills. To perform this program, six sessions of time-limited(100-150 minutes) were carried out. And the subjects were assigned to experimental group(N=4 couples) and control group(N=4 couples). Scales of PREPARE and SEI(Self-Esteem Inventory) were used as the pre-post-follow instruments of this study. Major findings were as follows: 1. Premarital Relationship Enrichment Program had meaningful consequences for the improvement of the participants self-esteem. 2. Premarital Relationship Enrichment Program had meaningful consequences for the improvement of the participants equal role, communication and conflict resolution skills.