• Korean System Dynamics Review
• /
• v.14 no.3
• /
• pp.105-134
• /
• 2013

Electrical construction business has public and professional characters. It may require appropriate interventions of the government because these business activities stand for not only profit-seeking competition, but also supplies of one of the key functions in our society. In other words, public benefit and private benefit are still in existence. The government therefore considers such an aspect of public importance of the business sector and needs to plan to adjust technical and engineering manpower of this market. This study focuses on the imbalance for labor supply and demand of technical engineer in electrical construction business. A system dynamics analysis is applied to understand and simulate the imbalance as a soft approach. It has the merit of causal loop diagram to alleviate the limitation of data lack problem. We find that excess demand is expected from 2010 to 2011, and excess supply is predicted from 2012 to 2021 about the manpower of technical engineer. It shows considerable disagreement between the supply and demand of human resource. So we suggest that it is strong necessity to construct statistics infrastructure for a manpower supply and demand plan.

• Korean System Dynamics Review
• /
• v.5 no.2
• /
• pp.149-174
• /
• 2004

Since the economic crisis in 1997, the Korean government has implemented a number of reforms in order to eliminate inefficiencies in both private and public sectors. One of the reforms made in the public sector was to lower the retirement age of teachers from the original age of 65 to that age 62. The ultimate aim of this compulsory policy was to improve the quality level of education by hiring many young teachers instead of senior teachers. It was made based on the calculation that by lowering the retirement age by three years, the government can hire three young teachers with the saved wages. However, this policy has brought an unexpected result; the imbalance between the supply and demand for teachers has become a much more serious problem in Korea's elementary education system The purpose of this study is largely twofold; First of all, it aims to identify the scope of imbalances occurred in the supply-demand system of elementary school teachers in a region of the nation, and also to find out why such imbalance occurred. Secondly, the purpose of this study is to experiment with feasible policy alternatives and their effects on the system and to suggest some resolutions on the imbalance.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.15 no.6
• /
• pp.440-448
• /
• 2022

Recently, due to the introduction of distributed energy resources, the optimal resource allocation problem of the power network is more and more important, and the distributed resource allocation method is required to process huge amount of data in large-scale power networks. In the optimal resource allocation problem, many studies have been conducted on the case when the supply-demand balance is satisfied due to the limitation of the generation capacity of each generator, but the studies considering the supply-demand imbalance, that total demand exceeds the maximum generation capacity, have rarely been considered. In this paper, we propose the consensus-based distributed algorithm for the optimal resource allocation of power network considering the supply-demand imbalance condition as well as the supply-demand balance condition. The proposed distributed algorithm is designed to allocate the optimal resources when the supply-demand balance condition is satisfied, and to measure the amount of required resources when the supply-demand is imbalanced. Finally, we conduct the simulations to verify the performance of the proposed algorithm.

• Proceedings of the KIPE Conference
• /
• 2017.07a
• /
• pp.216-218
• /
• 2017

The imbalance at the 3-phase side at the railway power supply substation has been a well-known issue. Due to the difference in status of loads at each phase at any given moment, it is difficult to maintain the balance in the 2-phase side of the transformer. Consequently, the 3-phase side also presents a certain level of imbalance as well. A co-phase power supply was proposed as a solution. The real application of such system is gradually expanding, proving the effectiveness of the system. In this paper, the application of the single phase D-Q rotating frame theory was applied to the control of the co-phase power supply system. In addition, the power stack of the system was composed of MMC valves, which offers superior operational characteristics. The effectiveness of the system was verified with a real-time simulation, and the results are presented.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.2
• /
• pp.511-517
• /
• 2015

Determination of the required reserve capacity has an important function in operation of power system and it is calculated based on the largest loss of supply. However, conventional method cannot be applied in future power system, because potential grid-connected distributed generator and abnormal temperature cause the large load imbalance. Therefore this paper address new framework for determining the optimal required reserve capacity taking into account the real time load imbalance. At first, we introduce the way of operating reserve resources which are the secondary, tertiary, Direct Load Control (DLC) and Load shedding reserves to make up the load imbalance. Then, the formulated problem can be solved by the Probabilistic Dynamic Programming (PDP) method. In case study, we divide two cases for comparing the cost function between the conventional method and the proposed method.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.23 no.3
• /
• pp.161-173
• /
• 2020

This study analyzed local imbalances in the supply and demand of emergency medical services in Busan using the 119 emergency activity reports of the Busan Fire & Disaster Headquarters. The data for EMS activity reports in 2017 was converted into Jimgyegu units. The spatial distribution of the indicators representing the local imbalance of emergency demand and supply (number of reports, number of reports relative to the population, average coefficient of variation and outlier of on-site arrival time, and number of dispatches outside the jurisdiction) was analyzed using Hotspot analysis of GIS spatial statistics analysis. As a result of the analysis, the hot spot area and the cold spot area where both supply and demand of emergency services are concentrated were clearly distinguished. This means that the supply and demand of emergency services in Busan are locally unbalanced. In particular, there was a difference in the demand and supply of emergency services in the original downtown and its surrounding areas, and in the outskirts of Busan.

• Journal of Technology Innovation
• /
• v.16 no.2
• /
• pp.201-223
• /
• 2008

This paper studies the supply and demand of Industrial Technology Labor-force(ITL) and analyzes the determinate of ITL shortage in Korean manufacturing. We classified the industry into four categories-high technology industries, medium-high technology industries, medium-low technology industries and low technology industries-based on its R&D intensity like OECD. For the empirical analyses we use a survey data collected from 5,703 enterprises. The key findings are as follows: Firstly, a large majority of ITL is engaged in more technology-intensive industries but the categories that are exposed to more serious labor-force shortage problem are medium-high technology industries and low technology industries. Secondly, in the terms of supply factor, the ITL shortage problems are mainly due to the avoidance of ITL jobs. And the demand point, the reason is that the most of ITL are not researchers but production managers. Thirdly, the cause of imbalance between supply and demand of ITL are different by the technological categories. For example, in the high technology industries, the supply factors, such as average wage and turnover rate played more important role in the imbalance. But in the low technology industries the demand factors, such as per capita sales and the ratio of ITL in all employees were relatively much more important. Based on the findings, we discovered some political meanings such as the necessity to plan various policies to resolve the shortage problem of ITL according to the technological categories, etc.

• Journal of Home Health Care Nursing
• /
• v.27 no.2
• /
• pp.137-145
• /
• 2020

Purpose: This study aimed to identify the training system and current status of home health nurses and to examine ways to retain sufficient number of advanced practice nurses (APNs) in the home health nursing field. Methods: This study analyzed the adequacy of the supply of home health nurse by reviewing the existing research literature and statistical data. Results: Discussions on how to revitalize the home care business have been ongoing since the beginning of 2001. However, despite home health nurses being oversupplied, discussions on the adequacy of supply have always been excluded from the focus of revitalization. The recent expansion of the home care business has resulted in a shortage of workforce, which can be inked not only to the continuous reduction of the designated quota of programs but also to the regional imbalance of educational institutions. The serious imbalance between supply and demand has caused fears that the home care business would drastically reduce. Conclusion: It is necessary to not only increase designated quotas for APNs programs but also integrate those programs of the similar curricula, thus lowering supply shortages in home health nurses.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.189-194
• /
• 2009

In a gas engine based cogeneration system, heat is recovered from two parts, which are jacket water and exhaust gas. The heat from the jacket water is often recovered by a plate type heat exchanger and used for the room heating and/or hot water supply. Depending on the operating conditions of engine and heat recovery system, there should be imbalance in the flow rate and supply pressure between engine and heat recovery side of the heat exchanger. The imbalance cause the deformation of the plate, which affects the pressure drop characteristics. In the present study, the pressure drop inside the heat exchanger has been investigated in a 1/5 scaled test rig and compare with the experimental correlations, which are used for the design.

• Asia pacific journal of information systems
• /
• v.29 no.2
• /
• pp.217-247
• /
• 2019

This paper draws on the interdependence theory to examine the role of power and mutual dependence on the relationship between internal/external diffusion and performance improvement within a supply chain. The results from a survey of 375 respondents show that two patterns of IOS diffusion - internal diffusion and external diffusion - have different impacts on a firm's performance improvement according to differences in power and mutual dependence between two parties in the supply chain.