• KEPCO Journal on Electric Power and Energy
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• v.2 no.4
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• pp.569-575
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• 2016

In this paper, we propose a method to develop a static equivalent model of an inverter-based distributed energy resource (DER), where the model is used for a steady-state fault analysis of a power grid. First, we introduce the characteristics of an inverter-based DER as well as its general configuration. Then, we derive the equivalent model of the DER on the basis of the characteristics. Last, the performance of the proposed method is proven by the results of computer simulations.

• Journal of the Optical Society of Korea
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• v.17 no.5
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• pp.405-409
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• 2013

In this paper, a unifying framework to evaluate the depth resolution of axially distributed image sensing (ADS) systems under fixed resource constraints is proposed. The proposed framework enables one to evaluate the system performance as a function of system parameters such as the number of cameras, the number of pixels, pixel size, and so on. The Monte Carlo simulations are carried out to evaluate ADS system performance as a function of system parameters. To the best of our knowledge, this is the first report on quantitative analysis of ADS systems under fixed resource constraints.

• Journal of Computing Science and Engineering
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• v.7 no.1
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• pp.44-52
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• 2013

This paper addresses the problem of resource scheduling in a grid computing environment. One of the main goals of grid computing is to share system resources among geographically dispersed users, and schedule resource requests in an efficient manner. Grid computing resources are distributed, heterogeneous, dynamic, and autonomous, which makes resource scheduling a complex problem. This paper proposes a new approach to resource scheduling in grid computing environments, the hierarchical stochastic Petri net (HSPN). The HSPN optimizes grid resource sharing, by categorizing resource requests in three layers, where each layer has special functions for receiving subtasks from, and delivering data to, the layer above or below. We compare the HSPN performance with the Min-min and Max-min resource scheduling algorithms. Our results show that the HSPN performs better than Max-min, but slightly underperforms Min-min.

• Journal of Korea Multimedia Society
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• v.6 no.6
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• pp.1100-1110
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• 2003

Design and implementation of remote procedure cail (RPC) resource service system based on the XML considering the request delegation between the servers are described for the resource application and efficient processing of distributed environment. For this purpose, the request information about several server, which would be used by client, is encoded into XML document based on XML-DOM and transferred to server. Server classifies the client requests using objects which can deal with the XMLL-DOM. For the request delegation between the servers, server saves the request result of client in XMLL-DOM structure without replying it immediately, and makes the client request delegated to another server in XML-DOM's request information. In addition, the resource repository are managed for resource transparency of distributed environment. As a result, resource application and processing efficiency are improved by reduction of response time caused by integration of RPC and XML-RPC services and request delegation between the servers. Extension of asynchronous and average blocking time of client were reduced and information of resource which can be used by client was offered.

• Journal of the Korea Society for Simulation
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• v.12 no.4
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• pp.51-59
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• 2003

Real-Time applications on Grid environment have several problems in terms of resource management addressed as follows; (1) dynamic resource allocation to provide QoS objectives, (2) heterogeneous resources that is different scale, or capacity in same unit, and (3) resource availability, and resource needs. This paper describes the techniques of resource manager (RM) handling above problems to support QoS of dynamic real-time applications on Grid. The contributions of this paper to solve problems are as follows: unification of dynamic resource requirements among heterogeneous hosts, control of resources in heterogeneous environments, and dynamic load balancing/sharing. Our heuristic allocation scheme works not only 257% better than random, 142% better than round robin, and 36.4% better than least load in QoS sensitivity, but also 38.6% better than random, 28.5% better than round robin, and 31.6% better than least load in QoS.

• Journal of Families and Better Life
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• v.10 no.2
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• pp.163-178
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• 1992

This study is focused on causual relationship analysis among the components of family resource management system based on a theory of Deacon and Firebaugh. The system of family resource management is consisted for the component of input like on objective resource and level of resource perception, the component of throughput like a behavior pattern of the family resource management, and the component of output like a degree of the family life satisfaction. The instrument for resource perception level, behavior pattern of family resource management and degree of life satisfaction were developed for this study, and main investigation was executed through 1st and 2nd pre-test. The 800 questionnaire were distributed by cluster sampling to the homemakers in Seoul. The final data used in this study were 703, and analyzed by Cronback's coefficient, factor analysis. frequency. percentage, regression analysis and path analysis, and teated with SAS PC+. Consequently , the findings of this study were accepted hypothesis I, II, II, IV.

• Journal of Korean Society for Quality Management
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• v.28 no.4
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• pp.29-46
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• 2000

Advent of the distributed computing has contributed to the rapid distribution of information technology throughout the organization. While powerful and user-friendly information technology are more available to end users, managing the distributed, heterogeneous IT environment has become a serious problem for corporate IT managers. Integrated Control Architecture (ICA) enables the monitoring and controlling of the dispersed information resources for effective enterprise-wide information resource management. This paper empirically examines the propositions that the level of information resource control is positively related to IS effectiveness measured in user satisfaction. Measures are developed and validated for the control of information resource object such as data, application, platform, and control of relationships among such objects. Results from a study of 130 organizations support that the organizations with high information resource control exhibit user satisfaction.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.5
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• pp.225-234
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• 2015

Nowadays a Virtual Power Plant (VPP) represents an aggregation of distributed energy resource such as Distributed Generation (DG), Combined Heat and Power generation (CHP), Energy Storage Systems (ESS) and load in order to operate as a single power plant by using Information and Communication Technologies, ICT. The VPP has been developed and verified based on a single virtual plant platform which is connected with a number of various distributed energy resources. As the VPP's distributed energy resources increase, so does the number of data from distributed energy. Moreover, it is obviously inefficient in the aspects of technique and cost that a virtual plant platform operates in a centralized manner over widespread region. In this paper the concept of the large-scale VPP which can reduce a error probability of system's load and increase the robustness of data exchange among distributed energy resources will be proposed. In addition, it can directly control and supervise energy resource by making small size's virtual platform which can make a optimal resource scheduling to consider of variable and sensitive load in the large-scale VPP. It makes certain the result is verified by simulation.

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.237-255
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• 2021

Lychnis wilfordii (Regel) Maxim. is one of the wetland specialists mainly distributed in peatlands at high latitudes. In Korea, it is isolated in two regions. This study investigated habitats, growth traits, and self-compatibility of L. wilfordii and assessed the internal dynamics of its population persistence. Its population has remained stable in the Yongneup Wetland Protected Area (YWPA). There was a clear difference in vegetation environment between YWPA and the distribution area in Daegwallyeong (DWL), Pyeongchang-gun. It has self-compatibility while pollinators facilitate its seed production. It produces a large number of hibernacles and bears the maximum number of branches and fruits in soil with rich organic contents. However, it grows and bears fruits even under the condition of low organic contents. In YWPA, L. wilfordii is not distributed in high moor but widely distributed in low moor where tussocks by Carex thunbergii var. appendiculata are developed. It is mainly distributed on the top of tussocks also. Therefore, it is judged that the formation, growth, and extinction of tussocks by C. thunbergii var. appendiculata is closely related to the establishment, growth, and extinction of plants distributed in this space. It is assessed that the current YWPA has well-developed tussocks in which L. wilfordii is widely distributed, and extinction and re-establishment progress well. Accordingly, the L. wilfordii population is expected to be sustainable in the long term given if its current ecological process is maintained well.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.2
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• pp.141-151
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• 2013

Process planning can be defined as determining detailed methods by which parts can be manufactured from the initial to the finished stage. Process planning starts with determining the manufacturing process based on the geometric shape of the part and the machines and tools required for performing this process. Distributed process planning enables production planning to be performed easily by combining the extracted process and various manufacturing resources such as operations and tools. This study proposes an algorithm to determine the process for a feature-based model and to combine manufacturing resources for the process and implements a distributed process planning system.