• Title/Summary/Keyword: Coordination number

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The Study on Factors Affecting Inter-agency Coordination in Family Violence (가정폭력 관련 기관들의 서비스 연계실태와 관련 요인)

  • Kim, Jae-Yop;Park, Soo-Kyeong
    • Korean Journal of Social Welfare
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    • v.47
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    • pp.107-147
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    • 2001
  • In the 1990s, with enacting of the laws on the family violence in Korea, agencies such as helpline 1366, counseling center and shelter for the female victims have been rapidly increasing in number. Also police and medical center have been viewed as having major responsibility for delivering services and social workers in community welfare center and public social worker have been expected play a role in community-based delivery systems for the female victims. The purpose of this study is to measure the level of the inter agency coordination and to find out the factors affecting the inter-agency coordination in family violence and to make policy implications for a better delivery system. The data were obtained from a social survey of family violence agencies, counselling center/shelter/helpline 1366, police, medical center, social workers of community center and of public sector in Seoul and Kyeongi area. The major results are as follows: 1) the level of inter-agency coordination is low, specially the referal cases of police and medical center is very poor. 2) The type of inter-agency coordination is referals and information sharing among agencies. 3) the factors affecting inter-agency coordination is agency type, wills and efforts of agency, information sharing, experience of family violence education. The current findings suggest that the delivery system to promote inter-agency coordination efforts and for police and medical center, social worker in private and public agency to respond promptly and properly would be built up.

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The effective recloser and sectionalizer coordination and protection scheme in distribution system interconnected a number of distributed resources (다수의 분산형 전원이 연계된 배전계통에서 리크로저와 섹셔널라이저의 보호협조 방안)

  • Jung, Hyun-Jun;Choi, Joon-Ho;Nam, Hae-Kon;Moon, Chae-Joo
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.429-431
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    • 2005
  • According to the second plan of the Korean Government about technology development, utilization and popularization of new renewable energy, the continuous growth of distributed resources are expected. Various studies about impact of distributed resource on distribution system have been already accomplished. Rut there is a few paper about recloser and sectionalizer coordination and protection scheme in distribution system interconnected a number of distributed resources. In this paper, it is dealt with that recloser and sectionalizer coordination at the cases concerned with fault position. The problems of these cases are investigated through simulation.

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A Dynamic Minimum Contention Window for Collision Resolution in IEEE 802.11 Distributed Coordination Function) (IEEE 802.11 Distributed Coordination Function에서 충돌방지를 위한 동적인 최소 경쟁윈도우의 적용)

  • Woo, Sung-Je;Lee, Tae-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.9A
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    • pp.1075-1082
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    • 2004
  • Wireless LAN is a rather mature communication technology connecting mobile terminals. IEEE 802.11 is a representative protocol among Wireless LAN technologies. The basic medium access control (MAC) mechanism of IEEE 802.11 is called distnbuted coordination function (DCF). DCF shows poor throughput and high drop rate as the number of stations and offered traffic load increase. In this paper we propose an effective mechanism using dynamic mimmum contention window(CWmin) in wireless LAN~ and show that performance improves via simulations. Proposed dynamic CWmin scheme exhibits superior performance as the number of stations and offered load grow. As, our proposed scheme is expected to be more effective in highly densed wireless LAN environment.

Optimization Methods for Power Allocation and Interference Coordination Simultaneously with MIMO and Full Duplex for Multi-Robot Networks

  • Wang, Guisheng;Wang, Yequn;Dong, Shufu;Huang, Guoce;Sun, Qilu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.1
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    • pp.216-239
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    • 2021
  • The present work addresses the challenging problem of coordinating power allocation with interference management in multi-robot networks by applying the promising expansion capabilities of multiple-input multiple-output (MIMO) and full duplex systems, which achieves it for maximizing the throughput of networks under the impacts of Doppler frequency shifts and external jamming. The proposed power allocation with interference coordination formulation accounts for three types of the interference, including cross-tier, co-tier, and mixed-tier interference signals with cluster head nodes operating in different full-duplex modes, and their signal-to-noise-ratios are respectively derived under the impacts of Doppler frequency shifts and external jamming. In addition, various optimization algorithms, including two centralized iterative optimization algorithms and three decentralized optimization algorithms, are applied for solving the complex and non-convex combinatorial optimization problem associated with the power allocation and interference coordination. Simulation results demonstrate that the overall network throughput increases gradually to some degree with increasing numbers of MIMO antennas. In addition, increasing the number of clusters to a certain extent increases the overall network throughput, although internal interference becomes a severe problem for further increases in the number of clusters. Accordingly, applications of multi-robot networks require that a balance should be preserved between robot deployment density and communication capacity.

Synergistic extraction of lanthanoids(III) with thenoyltrifluoroacetone and aromatic carboxylic acids and the hydration of the extracted species

  • Ishiwata, E.;Kimura, T.;Kato, Y.;Hasegawa, Y.
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.499-503
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    • 1995
  • In order to study how and why the stabilities of lanthanoid(III) complexes in solutions vary across the series, the formation constants of the adducts of tris(2-thenoyltrifluoroacetonato)lanthanoids(III) with seven carboxylic acids in chloroform have been determined by solvent extraction technique at 298K. The formation constants with carboxylic acids generally decrease with increasing the atomic number, but in the middle of the series, they change only slightly. Such trends have been interpreted as related to a change of the coordination number in the middle of the series. It has been attempted to determine the number of water molecules coordinated to the adducts as well as $Eu(TTA)_3$ in chloroform by measuring the fluorescence life time of europium(III), to ensure the assignment of the coordination number.

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First-principles Calculations of K-edge Absorption Spectra of Ca-bearing Minerals (Ca-함유 광물에 대한 제1원리 K-edge 흡수 스펙트럼 계산)

  • Sanggeon Kim;Sangbo Son;Kideok D. Kwon
    • Korean Journal of Mineralogy and Petrology
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    • v.37 no.2
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    • pp.13-22
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    • 2024
  • X-ray absorption near-edge structure (XANES) spectroscopy can provide qualitative insights into the coordination chemistry of calcium (Ca) across a variety of geological materials. However, systematic studies on Ca K-edge XANES spectral features and the Ca coordination parameters are rare. This study investigated potential correlations between the spectral features of Ca K-edge XANES and the coordination parameters of Ca for selected Ca-bearing minerals (anorthite, aragonite, calcite, diopside, dolomite, grossular, monohydrocalcite, perovskite, and wollastonite), employing density functional theory (DFT) calculations. DFT calculations accurately reproduced the main features of their experimental Ca K-edge XANES spectra for representative silicates, carbonates, and titanates. No strong correlation was observed between XANES peak positions vs. Ca-O distances (or Ca coordination numbers). However, a significant correlation was noted between the peak intensity of post-edge peaks vs. the effective coordination number of Ca in minerals of similar chemical compositions. These results show the potential, yet limited, applicability of XANES spectra for molecular-level research of Ca-bearing geomaterials, and highlight the critical role of DFT computations in interpretating XANES spectra.

Dissolution Monitoring of Geo-Soluble Mixtures (지반 소실 혼합재의 용해과정 모니터링)

  • Truong, Q. Hung;Byun, Yong-Hoon;Eom, Yong-Hun;Sim, Young-Jong;Lee, Jong-Sub
    • Journal of the Korean Geotechnical Society
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    • v.25 no.10
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    • pp.111-122
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    • 2009
  • Dissolution of some of geo-materials may yield the loss of the soil strength and the settlement of earth structures. The goal of this study is to monitor the several physical behaviors of soluble mixtures during dissolution. Sand-salt mixtures are used to monitor the meso to macro response including the settlements and shear waves. The mixtures of photoelastic and ice disks are used to monitor micro to meso behavior of soluble mixture including the void ratio, force chain, coordination number and horizontal force changes. In the sand-salt mixtures, shear waves are measured by using bender elements in conventional oedometer cells. In the photoelastic disk - ice disk mixtures, micro to meso response are measured by digital images and load cells. The shear wave velocity decreases at the initial stage of the dissolution, and then increases and approaches to asymptotic value. The larger dissoluble particle and the more random packing produces the severe horizontal fore change. After dissolution, the void increases and the coordination number decreases. This study demonstrates that the particle level behavior such as the changes of the force chain, void ratio, and coordination number affects the global behavior such as the change of the shear wave velocity and horizontal force of the system.

Effect of Artificially Decreased Visual Acuity upon Eye-Hand Coordination using Lee-Ryan Eye-Hand Coordination Test (Lee-Ryan Eye-Hand Coordination Test를 이용한 인위적 시력저하가 눈-손 협응능력에 미치는 영향)

  • Lee, Ki-Seok
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.3
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    • pp.371-376
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    • 2014
  • Purpose: The aim of this study was to explore the effect of artificially decreased eye in normal vision on eye-hand coordination (EHC) when using the Lee-Ryan Eye-Hand Coordination Test recently reported. Methods: Eleven adults with normal vision aged $29.46{\pm}5.94$ years participated for this study where a non-dominant eye artificially induced moderate refractive amblyopic vision at near by adding a plus lens conducted EHC tasks and then did the test again under normal vision following 2 weeks. To investigate the ability of EHC, 7 tasks including individually different level of difficulty in the Lee-Ryan EHC Test were selected to compare and analyze EHC in terms of two independent variables such as time taken and the number of errors. Results: In time taken, subjects with artificially decreased vision took more time than normal vision under monocular conditions (p=0.013), while those with the decreased vision completed their tasks faster than normal vision under binocular conditions (p=0.001). In the number of errors, subjects with the decreased vision made more mistakes (p<0.001) as shown in time taken, whereas there was no difference between monocular and binocular viewing conditions in the decreased vision. Conclusions: Unlike previous EHC tests including limitations for application, deficit in EHC can be screened by the Lee-Ryan EHC Test developed based on simple computer-based system. Therefore, it is considered that further studies relevant to deficits in visual function such as amblyopia will be carried out in clinics as well as research.

Evaluation of Coordination of Emergency Response Team through the Social Network Analysis. Case Study: Oil and Gas Refinery

  • Mohammadfam, Iraj;Bastani, Susan;Esaghi, Mahbobeh;Golmohamadi, Rostam;Saee, Ali
    • Safety and Health at Work
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    • v.6 no.1
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    • pp.30-34
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    • 2015
  • Background: The purpose of this study was to examine the cohesions status of the coordination within response teams in the emergency response team (ERT) in a refinery. Methods: For this study, cohesion indicators of social network analysis (SNA; density, degree centrality, reciprocity, and transitivity) were utilized to examine the coordination of the response teams as a whole network. The ERT of this research, which was a case study, included seven teams consisting of 152 members. The required data were collected through structured interviews and were analyzed using the UCINET 6.0 Social Network Analysis Program. Results: The results reported a relatively low number of triple connections, poor coordination with key members, and a high level of mutual relations in the network with low density, all implying that there were low cohesions of coordination in the ERT. Conclusion: The results showed that SNA provided a quantitative and logical approach for the examination of the coordination status among response teams and it also provided a main opportunity for managers and planners to have a clear understanding of the presented status. The research concluded that fundamental efforts were needed to improve the presented situations.