• Journal of the Korea Society for Simulation
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• v.27 no.2
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• pp.71-81
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• 2018

Forklifts in a shipyard lift and transport heavy objects. Tasks occur dynamically and the rate of the task occurrence changes over time. Especially, the rate of the task occurrence is high immediately after morning and afternoon business hours. The weight of objects varies according to task characteristic, and a forklift also has the workable or allowable weight limit. In this study, we propose an online forklift dispatching algorithm based on nearest-neighbor dispatching rule using minimal cost assignment approach in order to attain the efficient operations. The proposed algorithm considers various types of forklift and multiple jobs at the same time to determine the dispatch plan. We generate dummy forklifts and dummy tasks to handle unbalance in the numbers of forklifts and tasks by taking their capacity limits and weights. In addition, a method of systematic forklift selection is also devised considering the condition of the forklift. The performance indicator is the total travel distance and the average task waiting time. We validate our approach against the priority rule-based method of the previous study by discrete-event simulation.

• Proceedings of the KWS Conference
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• 2000.10a
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• pp.13-18
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• 2000

Welding is critical technique for the joining of materials in the nation's major Manufacturing industries. Since 1998, leaders in welding industry have defined a vision of the issues and opportunities that it will face in 2020. In developing this vision document, more than 25 senior managers and respected experts from various segments of the welding community met to begin a dialog about the future of the welding industry. They were brought together to develop a long-range business plan for their industry that would identify how it would meet the needs of manufacturers, of the marketplace, and of society in 2020. In essence, these decision makers created an ideal vision of the state of their industry in 20 years, and the strategy to reach it. Welding is a precise, reliable, and cost-effective, method for joining materials. No other technique is as widely used by manufacturers to join metals and alloys efficiently. Most of the familiar objects in modern society, form buildings and bridges, to vehicles, computers, and medical devices, could not be produced without the use of welding. Despite the importance of welding to the manufacturing industry, the leaders in this area felt that welding was not appreciated as much as it should be from the society. The welding industry consists of the “users” of welding techniques as well as the companies, universities and other organizations that industry look for improvements in their operations by 2020, and should find their interest addressed in this document. A major economic impact study co sponsored by AWS and EWI and supported by US Navy, State of Ohio, US Department of Commerce, and major companies was kicked off. This two-year study will determine the economic impact of welding on the United States economy. The objective of this study is to break a paradigm about welding-those of us who are heavily involved in welding, believe strongly that much of our gross domestic product is directly dependent on welding. Furthermore, continued advances in the field of welding are necessary to achieving further increases in productivity that makes our economy strong. Yet, despite intuition, anecdotal information, and fragmented analyses, the completing quantitative information that would proved the justification for strategic actions to further develop this critical field is not currently available.

• Journal of Digital Convergence
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• v.16 no.3
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• pp.291-301
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• 2018

Supply chain in service sector has been established on the premise that firms need to manage their process uncertainties to satisfy customers in an efficient manner. Information sharing and synchronization play key roles in minimize uncertainties from their involved supply chain. The duality of customers being inputs providers as well as consumers, differentiates service supply chains from manufacturing and is a challenging issue to traditional supply chain management. The service supply chain is a structured network which should be managed with supply chain theory and principles. Various key operations need to be carried out through a highly integrated and collaborated service supply chain and supporting information hub. The purpose of this paper is to present the issues and key components in the service supply chain, where the repetitive service is provided along the value chain, such as tourism, restaurant, mega-sized hospital supply chain.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.393-401
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• 2017

Assuming that Smart Work will have a positive effect on job satisfaction, and which, in turn, will improve productivity, domestic and international organizations have adopted and implemented Smart Work. However, leading companies have recently reduced or shut down operations of Smart Work. If Smart Work had really brought about the improvement of productivity, there would be no reason for organizations to take such action. Therefore, this paper reviews the relationship among Smart Work, job satisfaction and productivity. Based on the National Digital Science Library (NDSL) database, we select eight references related to Smart Work, and analyze them systematically. The previous empirical studies show that Smart Work produces a positive outcome for job satisfaction, which, in turn, improves productivity. However, we find that the previous research has a problem demonstrating the relationship between job satisfaction and productivity, because they has unclearly measured the concept of job satisfaction. This research deeply discuss this issue, and provides future research direction.

• Journal of the Korea Convergence Society
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• v.11 no.7
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• pp.231-238
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• 2020

In the case of ICT-enabled organizational changes such as Smart Work, appropriate change management is required. To achieve work-life balance, organizational change management should be conducted from both a structural and a cultural perspective. This study looked at organizational factors that affect Smart Work facilitation through a case study with the view of ICT-enabled change management. From November to December 2019, eight Smart Workers of Company A were interviewed and analyzed for organizational support. The results show that structural support such as institutionalization, ICT infrastructure office environment improvement, Smart Work center as well as cultural support such as enhancing autonomy, communicating style of managers, trusting organizational climate are required. The findings suggest balanced organizational support to provide cultural support along with structural support for activating Smart Work operations. In the future, it is necessary to demonstrate the causality between structural/cultural support factors and outcome factors.

• Journal of Digital Convergence
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• v.18 no.5
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• pp.1-8
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• 2020

This study analyzed the different needs between the after-school programs of elementary schools in metropolitan and non-metropolitan areas to understand the areas that need addressing to meet with the requisites of the programs. To this end, this study conducted a survey among teachers with experience in after-school management (n=233), and the needs and performance recognized by teachers were analyzed in the IPA model matrix. To sum up the results, 'Online educational infrastructure', 'Efficient administrative operation', and 'Supply of professional after-school instructors' were identified as the prior needs in metropolitan area. On the other hand, non-metropolitan area, 'Supply of professional after-school instructors', 'Quality educational contents', and 'Online educational infrastructure' were identified as the prior requisites to be addressed. Based on research findings, the study suggested implications in developing and implementing related policies. Research findings will be expected to refer as baseline data for activating after-school online program operations and improving its programs to meet with the different needs of regions.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.138-149
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• 2016

Quality function deployment (QFD) is a widely adopted customer-oriented product development methodology by translating customer requirements (CRs) into technical attributes (TAs), and subsequently into parts characteristics, process plans, and manufacturing operations. A main activity in QFD planning process is the determination of the target levels of TAs of a product so as to achieve a high level of customer satisfaction using the data or information included in the houses of quality (HoQ). Gathering the information or data for a HoQ may involve various inputs in the form of linguistic data which are inherently vague, or human perception, judgement and evaluation for the information and data. This research focuses on how to deal with this kind of impreciseness in QFD optimization. In this paper, it is assumed as more realistic situation that the values of TAs are taken as discrete, which means each TA has a few alternatives, as well as the customer satisfaction level acquired by each alternative of TAs and related cost are determined based on subjective or imprecise information and/or data. To handle these imprecise information and/or data, an approach using some basic definitions of fuzzy sets and the signed distance method for ranking fuzzy numbers is proposed. An example of a washing machine under two-segment market is provided for illustrating the proposed approach, and in this example, the difference between the optimal solution from the fuzzy model and that from the crisp model is compared as well as the advantage of using the fuzzy model is drawn.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.9
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• pp.409-418
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• 2020

The human and capital resources from foreign investors are important sources of finance for developing countries. Foreign ownership can help the firm to raise funds for operations and the foreign management can help the firm expand the market and improve management. However, does this really happen to Vietnamese firm? To find the answer to that question, this paper examines the impact of foreign ownership and management on the financial performance of listed firms on Vietnam's stock market. The data collected include 427 listed firms in all fields over five years, from 2014 to 2018. The financial performance is measured by Tobin's Q, ROA and ROE. The study carried out testing of each model by the least squares method of Pool OLS, assessing random effects (REM) and evaluating fixed effects (FEM). The most effective model is the FEM model. The results show that the foreign ownership ratio and the size of the firm have a positive impact on the financial performance. The foreign management, the age of the firms, the liquidity and financial leverage have a negative impact on the financial performance. Based on the research results, the study proposes some recommendations to improve the financial performance of listed firms in Vietnam.

• The Journal of Information Systems
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• v.27 no.2
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• pp.95-114
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• 2018

Purpose The recent concern over environmental problems such as greenhouse gas emission and fine dust contributes increasing interest in renewable energies. However the intrinsic characteristics of renewable energies, intermittent and stochastic generation, might cause serious problems to the stability and controllability of power grid. Therefore countermeasures such as virtual power plant (VPP) must be prepared in advance of the spread of uncontrollable distributed renewable energy resources to be one of major energy sources. Design/methodology/approach This study deals with the design concept of the VPP platform. we proposed as a technology solution for achieving the stability of power grid by guaranteeing a single power profile combining multiple distributed power sources with ICT. The core characteristics of VPP should be able to participate in the grid operation by responding to operation instructions from the system operator, KPX, as well as the wholesale electricity market. Findings Therefore this study includes energy storage device(ESS) as a controllable component as well as renewable energy resources such as photovoltaic and wind power generation. Based on this configuration, we discussed core element technologies of VPP and protype design of VPP solution platform according to system requirements. In the proposed solution platform, UX design for the integrated control center and brokerage system were included as well as ancillary service function to respond to KPX's operation instruction with utilizing the capability of ESS. In addition, a simulator was suggested to verify the VPP operations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.10
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• pp.2396-2402
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• 2015

Air compressor, as an essential equipment used in the factory and plant operations, accounts for around 30% of the total electricity consumption in U.S.A, thereby being proposed advanced technologies to reduce electricity consumption. When the fluctuation of the compressed airflow rate is small, the system stability is increased followed by the reduction of the electricity consumption which results in the efficient design of the energy system. In the statistical analysis, the normal distribution, log normal distribution, gamma distribution or the like are generally used to identify system characteristics. However a single distribution may not fit well the data with long tail, representing sudden air flow rate especially in extremes. In this paper, authors decouple the compressed airflow rate into two parts to present a mixture of distribution function and suggest a method to reduce the electricity consumption. This reduction stems from the fact that a general pareto distribution estimates more accurate quantile value than a gaussian distribution when an airflow rate exceeds over a large number.