• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.3
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• pp.132-140
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• 2006

Forest vegetation classification and species composition of Mt. Ilwol, Yeongyang-Gun, Korea, were studied combining the Braun-Blanquet approach with numerical syntaxonomical analyses (TWINSPAN). Vegetation types and various ecological characteristics such as flora, constancy classes, species ratio of life-form, species diversity and importance value were analyzed. Sixty-eight samples were taken from a $100m^2$ square plot each. Forest communities were identified as two great types: arid landform of mountainside (AM) and humid fertility of piedmont and valley (HP). The former was divided into 3 communities (Rhododendron mucronulatum, Quercus variabilis, Hosta capitat community) and 2groups, and the latter into 3 communities (Tilia amurensis, Vitis coignetiae, Philadelphus schrenckii community) and 2 groups. Vegetation was classified into 8 units. Floristically, the most represented family was Compositae with 26 species. Species with percentage constance degree of more than 61% was Quercus mongolica (72.1%, IV); Carex siderosticat (III) and Fraxinus rhynchophylla (III) were 50.0 and 41.1%, respectively. Life-forms species ratios for trees, subtrees, shrub, vines, grominoids, forbs and ferns were 18.5, 5.7, 14.9, 6.6, 8.8, 42.4 and 3.1%, respectively, PH type showed from $1.70{\pm}0.50\;to\;1.97{\pm}0.57$ and AM type was from $1.40{\pm}0.18\;to\;1.62{\pm}0.20$ in species diversity; therefore, the former type showed higher species diversity than the latter, According to importance value analysis, Pinus densiflora, Quercus mongolica and Q. variabilis were higher in the tree layer, Q. mongolica in the subtree layer, Fraxinus sieboldiana, R. schlippenbachii, etc. in the shrub layer and Carex siderosticta, Carex humilis, etc. in the herb layer.

• Economic and Environmental Geology
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• v.44 no.4
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• pp.303-312
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• 2011

Analysis of high-resolution seismic profiles from the southeastern continental shelf of Korea reveals that the Holocene transgressive deposits consist of five sedimentary units characterized by retrograding or backstepping depositional arrangements. Unit I, forming a linear sediment body along the shelf margin, is an ancient beach/shoreface deposit formed during the early stage of transgression. During the transgression, the paleo-channels were backfilled with fluvial or coastal-plain sediments, forming Unit II as an incised-channel fill deposit. The near-surface sediment was reworked and eroded by shoreface erosion, forming a thin lag of sands (Unit III) on the midshelf. During the middle stage of the transgression, the shoreline may have stabilized at around 70 - 80 m below the present sea level for some period of time to allow the formation of sand ridge systems (Unit IV). Unit V in the inner shelf was deposited in an estuarine environment during the middle to late stage of transgression. Such transgressive stratigraphic architecture is controlled by a function of lateral changes in the balance among rates of relative sea-level rise, sediment input and marine processes at any given time.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.64-71
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• 2018

Project Management Institute of America separates the types of risk with external risks and internal risks. The external risk is an uncontrollable risk in projects such as changes of policy and related systems, climate, natural disasters, exchange rates and so on. The internal risk is an existing risk in the project itself that is controllable items in the project. Technical risks in project management are cost, quality, time, safety and environment. Therefore, both the external and internal risks should be managed to perform the construction project successfully. In particular, we can secure the quality and safety of facilities through the technical risk management. The importance of potential risk management has been emerging as a major interest and the lack of risk management delays projects and increases construction costs with negative effects of the building safety since the complex building, which is composed of a great number of facilities, consists of many project units and there are conflicts between various participants and stake-holders. This study presents the ways of establishing risk management processes to ensure the safety of the complex building. To that end, establishing procedure of risk management processes is presented and types of risk and factors in construction projects and counter strategies are presented as available risk information on the stages.

• Journal of Navigation and Port Research
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• v.30 no.8 s.114
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• pp.623-629
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• 2006

Recently, bemuse of extensive use of hydrographic information, interoperability of Marine Geographic products is very important for efficient use of geographic information systems. Open GIS Consortium(OGC) developed the Open Geodata Interoperability Specification(OpenGIS) to support the interoperability in the distributed environment, especially Geography Markup Language(GML) Implementation Specification. Geography Markup Language is an XML grammar written in XML Schema for the modelling, transporting, and storing of geographic information GML provides a variety of objects for describing geography including features, coordinate reference systems, geometry, topology, time, units of measure and generalized values. S-57 is currently the IHO standard for the exchange of digital hydrographic data. To date, it ms been used almost exclusively for encoding Electronic Navigational Charts(ENCs). Even though, S-57 is intended to support all types of hydrographic data. In order to meet this requirement, a new standard is being developed. GML will be the core encoding rule of IHO's new standard. But there has been no study that tried to develop the GML for ENC that are recognized as base mop in the Marine GIS. This paper presents the process and results on development of application schema for converting ENC into GML.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2A
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• pp.121-127
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• 2010

In this paper, we propose a computationally efficient scheduling algorithm that can arbitrarily control the throughput-fairness tradeoff in a multiuser wireless communication environment. As a new scheduling criterion, we combine linearly two well-known scheduling criteria such as one of achieving the maximum sum throughput and the other of achieving the maximum fairness, so as to control the relative proportion of the throughput and the fairness according to a control factor. For linear combining two different criteria, their optimization directivenesses and the units should be unified first. To meet these requirements, we choose an instantaneous channel capacity as a scheduling criterion for maximizing the sum throughput and the average serving throughput for maximizing the fairness. Through a unified linear combining of two optimization objectives with the control factor, it can provide various throughput-fairness tradeoffs according to the control factors. For further simplification, we exploit a high signal-to-noise ratio (SNR) approximation of the instantaneous channel capacity. Through computer simulations, we evaluate the throughput and fairness performances of the proposed algorithm according to the control factors, assuming an independent Rayleigh fading multiuser channel. We also evaluate the proposed algorithm employing the high SNR approximation. From simulation results, we could see that the proposed algorithm can control arbitrarily the throughput-fairness performance between the performance of the scheduler aiming to the maximum sum throughput and that of the scheduler aiming to the maximum fairness, finally, we see that the high SNR approximation can give a satisfactory performance in this situation.

• Journal of Digital Contents Society
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• v.17 no.1
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• pp.51-57
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• 2016

Distributed Computing attempts to harness a massive computing power using a great numbers of idle PCs resource distributed linked to the internet and processes a variety of applications parallel way such as bio, climate, cryptology, and astronomy. In this paper, we develop internet-distributed computing environment, so that we can analyze High Resolution Rainfall Prediction application in meteorological field. For analyze the rainfall forecast in Korea peninsula, we used QPM(Quantitative Precipitation Model) that is a mesoscale forecasting model. It needs to a lot of time to construct model which consisted of 27KM grid spacing, also the efficiency is degraded. On the other hand, based on this model it is easy to understand the distribution of rainfall calculated in accordance with the detailed topography of the area represented by a small terrain model reflecting the effects 3km radius of detail and terrain can improve the computational efficiency. The model is broken down into detailed area greater the required parallelism and increases the number of compute nodes that efficiency is increased linearly.. This model is distributed divided in two sub-grid distributed units of work to be done in the domain of $20{\times}20$ is networked computing resources.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.342-351
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• 1999

The forest vegetation developing on Mt. Inwang, an isolated forestland in Seoul, Korea was analyzed phytosociologically and its spatial distribution mapped out. Using the vegetation map, The characteristics of landscape structures in terms of the number and size of patches are discussed. Forest vegetation of the study area was classified into ten communities, ten groups, and eighty subgroups. Landscape element types were classified into secondary forests, relict communities, introduced plantations, and other elements including urbanized area. Pinus densiflora community, natural forest and Robinia pseudo-acacia community, plantation, formed matrix and some secondary forest elements, relict communities and the ether plantations of small size tended to distribute as small patches in such matrix. The number of patches per unit area in secondary forest elements was more than that in plantation elements. The result in patch size was vice versa. The vascular plant species richness of the landscape element types in Mt. Inwang was found to he positively related to their size. As the results of landscape ecological analyses, it was estimated that differentiation of patches recognized in community level would be related to human interference a and those in subordinate levels to natural process such as progression of succession.

• Journal of Korean Clinical Nursing Research
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• v.23 no.1
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• pp.9-19
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• 2017

Purpose: This study aimed to identify multidimensional factors influencing burnout in intensive care unit(ICU) nurses. Methods: A descriptive cross-sectional design was used. Data were collected during February 2016 from a convenience sample of 222 tertiary hospital ICU nurses and analyzed using t-test, ANOVA, correlation analysis, and multiple regression analysis. Results: Burnout correlated positively with compassion fatigue (CF)(r=.37, p<.001), and negatively with compassion satisfaction (CS)(r=-.66, p<.001). The regression model explained 57% of the variance in burnout. For individual characteristics in the model, perceived health status (${\beta}=-.27$, p<.001) and gender (${\beta}=.14$, p=.028) were the most influential factors for ICU nurses' burnout. In the model with added work-related characteristics, nursing environment (${\beta}=-.22$, p=.001), perceived health status (${\beta}= -.20$, p=.001), and satisfaction with department (${\beta}=-.19$, p=.007) were the most influential factors. Finally, for the model with psychological characteristics added, CS (${\beta}=-.56$, p<.001) and CF (${\beta}=.35$, p<.001) were the most influential factors. Conclusion: Results reveal that most ICU nurses have a moderate level of CF and a moderate to high level of CS and burnout, and that individual, work-related and psychological factors are relevant in ICU nurses' burnout. Programs or interventions to reduce burnout should be developed taking into account these multidimensional factors.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.7
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• pp.56-64
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• 2012

A smart grid is the next generation power grid which combines the existing power grid with information technology, so an energy efficient power grid can be provided. In this paper, in order to build an efficient smart grid an AMI system, which gears with the existing home network and provides an user friendly management function, is proposed. The proposed AMI system, which is based on an extended home network, consists of various functional units; smart meters, communication modules, home gateway, security modules, meter data management modules (MDMM), electric power application modules and so on. The proposed home network system, which can reduce electric power consumption and transmit data more effectively, is designed by using IEEE 802.15.4. The extended home gateway can exchange energy consumption information with the outside management system via web services. The proposed AMI system is designed to enable two-way communication between the home gateway and MDMM via the Internet. The AES(Advanced Encryption Standard) algorithm, which is a symmetric block cipher algorithm, is used to ensure secure information exchange. Even though the results in this study could be limited to our experimental environment, the result of the simulation test shows that the proposed system reduces electric power consumption by 4~42% on average compared to the case of using no control.

• Journal of Forest and Environmental Science
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• v.23 no.2
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• pp.109-118
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• 2007

This study was conducted to provide the fundamental data of the policy plan for the security of forestry labour and the revitalization of forestry mechanization by analysing the status of forestry labor and the training plan. In forestry, the total number of employer and the labour cost have slightly increased annually, but the number of employer for timber harvesting has decreased. Therefore, the organization of expert forestry mechanization unit and the training of operator will be necessary. The number and person of forest management unit, the working days of the year and income have increased in Korea. However, the working days per month of forest management unit were only 15 days, which are only 180 days per year. In the results of the calculated number and person of forest management unit for the Korean forest tending volumes, about 349 forest management units are required. In case of adjusting 12 persons per 1 unit, 4,185 persons are required. In calculated results of the optimum forestry mechanization unit and member's number by the adjusting of tower yarder harvesting system for annual timber harvesting production volume, it was known to necessary the 250 forestry mechanization unit and the 1,250 members which are calculated at 5 persons per 1 group.