• Asia pacific journal of information systems
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• v.33 no.2
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• pp.298-317
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• 2023

This study is about the attitudes and intentions of consumers considering the usage of O2O application (app) under the COVID-19 situation. By integrating TAM and TPB as a theoretical background, we selected VPC (various product choice) and PII (product information intensity) as new functional external variables that have a positive effect on new system called O2O commerce. We also applied the transaction cost theory to investigate the obstacle of O2O business. We conducted a survey of consumers in large cities in the Korean market. As a result of this study, it was found that the more O2O app users recognized the influence of SN (subject norms), the more useful O2O app was, the more it led to a change in attitude and usage intention was positively significant. In addition, as the O2O app was easy to use and useful, and the SN was recognized, the user's attitude was positive. On the other hand, it was also found that the transaction cost that consumers have to pay had a negative effect on usage intention. Additionally, VPC and PII have been shown to positively influence on usefulness of O2O apps.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.721-733
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• 2023

As the frequency of extreme rainfall events increase due to climate change, climate change adaptation measures have been proposed by the central and local governments. In order to reduce flood damage in urban areas, various flood response policies, such as low impact development techniques and enhancement of the capacity of rainwater drainage networks, have been proposed. When these policies are established, regional characteristics and policy-effectiveness from the cost-benefit perspective must be considered for the flood mitigation measures. In this study, capacity enhancement of rainwater pipe networks and low impact development techniques including green roof and permeable pavement techniques are selected. And the flood reduction effect of the target watershed, Gwanak campus of Seoul National University, was analyzed using SWMM model which is an urban runoff simulation model. In addition, along with the quantified urban flooding reduction outputs, construction and operation costs for various policy scenarios were calculated so that cost-benefit analyses were conducted to analyze the effectiveness of the applied policy scenarios. As a result of cost-benefit analysis, a policy that adopts both permeable pavement and rainwater pipe expansion was selected as the best cost-effective scenario for flood mitigation. The research methodology, proposed in this study, is expected to be utilized for decision-making in the planning stage for flood mitigation measures for each region.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1164-1167
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• 2003

Recently CRT is getting flatted, As change of CRT trend from normal type to Flat type, the material of Shadow Mask was also changed from AK(Aluminum Killed) to Invar(Fe-Ni alloy) materials Until now we have used just AK(Aluminum Killed) for normal type TV(not flat type), but main raw material of shadow mask component was changed. . However recently Invar(Fe-Ni alloy) materials, which has advantage of Low Thermal Expansion and High Strength, has been developed as well as applying in mass production as CRT's trend has become more flat and fine pitch. As main raw material of shadow mask component was changed, conditions of process were changed. One of them, the importance of pre-etching process (assistant process for developing & etching) is improved because there are so many particles in the pre-etching bath because of Ni compounds. Since the solubility of Ni in pre-etching solvent is very low related to Fe's, so the compounds of Ni happen to make particles.(the solubility of Fe is twenty times Ni's) that particles happen to make process troubles and NG productions so to clear the particles we had to established high cost filtering system, but it is useless. As time goes by the quantity of particles (Ni compounds) was increased because of the capability of filtering system was not enough, the particles was produced continuous in bath, and it make quality problems. Hence we tried to develop the new pre-etching solution to remove the particles (Ni compounds) and to cost down the filtering system's running cost. But in improving the solution we discovered the new pre-etching solution made the PR developing better. In former solution there were three kinds of chemistry (COOH)2 , H2O2 , H2S04 .first the function of (COOH)2 is drilling the surface of Invar, during this mechanism Ni compounds occurred. Second the function of H202 is removing the PR fringe (half UV exposure zone on PR(PVA)), Third the function of H2S04 is the catalysis of (COOH)2 In those, (COOH)2 was the main reason to make the Ni compounds. So to improve the solutions we had to change (COOH)2 to the other material. the chemistry we improved was a complex chemistry based on H2S04 . after using this chemistry the particles problem was disappeared and there was another advantage cut down the PR fringe. The New solution made the function of H202 better so the PR developing improved. To be direct the catalyst of the new solution helped the H202. anyway First thing after change the solution the quality of shadow Mask for flat color TV was improved & the yield also improved. But the more important thing is how to control the new solution. So we accepted the new concept which was the degree of freshness. The degree of freshness is based on non-reacted solution which was 100% ( the degree of freshness) and calculated the melted Ni quantity as time goes by. So we made the gauging liner plot. In conclusion, many companies tried to make fine pitched Shadow Mask ,generally to make quality jump up it needed a lot of cost & persons .in this case the shift of core material made it possible.

• The Journal of Society for e-Business Studies
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• v.24 no.3
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• pp.19-33
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• 2019

Recently, manufacturers have been struggling to efficiently use production equipment as their production methods become more sophisticated and complex. Typical factors hindering the efficiency of the manufacturing process include setup cost due to job change. Especially, in the process of using expensive production equipment such as semiconductor / LCD process, efficient use of equipment is very important. Balancing the tradeoff between meeting the deadline and minimizing setup cost incurred by changes of work type is crucial planning task. In this study, we developed a scheduling model to achieve the goal of minimizing the duedate and setup costs by using reinforcement learning in parallel machines with duedate and work preparation costs. The proposed model is a Deep Q-Network (DQN) scheduling model and is a reinforcement learning-based model. To validate the effectiveness of our proposed model, we compared it against the heuristic model and DNN(deep neural network) based model. It was confirmed that our proposed DQN method causes less due date violation and setup costs than the benchmark methods.

• KIEAE Journal
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• v.8 no.5
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• pp.69-76
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• 2008

Recent industrial development and technological breakthroughs have made our life much more convenient, however, at the cost of environmental degradation resulting from indiscreet focus on development in combination of disregard of impact on eco system. Notably, global warming is one of the most serious environmental issues, triggering attention for environmental protection in Korea and elsewhere. To address such issues, nations around the world are beefing up environmental regulatory framework such as UNFCCC(United Nations Framework Convention on Climate Change) to tackle environmental challenges from global perspective. Against the backdrop, Korea has been engaging actively in global initiatives to reduce climate change, ratifying UNFCCC in 1993 and the Kyoto Protocol in October, 2002. However, unlike the government responding to environmental degradation in earnest, construction industry is far from making efforts to reduce wastes. Construction waste is a source of environmental deterioration world wide and adds to the aggregate cost that construction companies should assume. Korean construction firms also need to develop initiative aggressively to respond to changes in environmental policies and reduce construction costs. Therefore, this study aims at examining sources of wastes in construction sites and suggest solution in order to prod local construction companies to develop countermeasures.

• Health Policy and Management
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• v.27 no.1
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• pp.80-83
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• 2017

The proportion of people who reported unmet healthcare needs is an important indicator to measure the access problem in healthcare service. To examine current status and trends of unmet needs in Korea, we used data from four sources: the Korea National Health and Nutrition Examination Survey (KNHNES, '2007-2015); the Community Health Survey (CHS '2008-2015); the Korea Health Panel Survey (KHP '2011-2013); the Korean Welfare Panel Study (KOWEPS '2006-2015). The proportion of individual reporting unmet healthcare needs as of 2015 was 12.6% (KNHNES), 11.7% (CHS), and 16.3% (KHP, as of 2013). Annual percent change which characterizes trend for follow-up period was -9.4%, -3.4%, and 7.6%, respectively. The proportion of individual reporting unmet healthcare needs due to cost was 2.8% (KNHNES), 1.7% (CHS), and 4.6% (KHP). The proportion of household reporting unmet healthcare needs due to cost was 1.2% (KOWEPS). Annual percent change was -9.0%, -14.9%, 9.4%, and -18.2%, respectively. Low income population reported about 5 times more unmet needs than high income population. Therefore for decreasing the unmet healthcare needs, strategies focusing on low income population were needed.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.647-654
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• 2005

Recently, the economic losses caused by inundation are increasing due to the urbanization and industrialization, i.e., intensive land utilization and concentration of population and properties. It is regarded that the role of the storm sewer systems in urban areas becomes more important as one of the effective countermeasures for reducing the inundation losses. In this study, the effects of rainfall design frequency enhancement on the construction cost of the storm sewer systems were analyzed by increasing the design frequency from the present design frequency of the sewer systems, which is 5~10 years, to 15 years, 20 years and 30 years. The change rate functions of the design discharge and construction cost based on the various design frequencies were derived by regression analysis. According to the analysis, change the rate of design discharge at 15, 20, 30 years rainfall design frequencies were increased by 10%, 17.1%, and 27.2%, respectively, when compared to that at 10 year frequency. Furthermore, it was found that by increasing the design frequency from 10 years to 15 years, 20 years and 30 years, the construction costs were increased by 5.0%, 8.0% and 12.4%, respectively. Finally, their reliabilities need to be tested by applying the rate functions to the real storm sewer districts.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.3
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• pp.79-98
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• 2004

Despite its contribution to the Korean medical service industry the question of how efficiently the Korean public hospitals have operated has been unresolved. This study gauges and analyzes the overall efficiency and the Malmquist productivity index in the industry over the period 1992 through 2001. In addition to cost efficiency. we also measure technical, allocative, pure technical and scale efficiencies. Furthermore. the Malmquist index is decomposed into efficiency and frontier changes. We identify several important factors which seem to have strong relationship with various inefficiency estimates. The results indicate that on average the public hospitals has wasted a significant amount of resources and costs over the period. Unlike many other industries, the low level of cost efficiency of the public hospital industry is mainly due to allocative inefficiency rather than technical inefficiency. The Maimquist productivity indices seem both due to the frontier change and efficiency change, but with more effect by the former. The results also indicate that the turnover of hospital beds has played an important role in determining efficiency and productivity of this important industry.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.110-113
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• 2000

In general, speed control method of the elevator system has used motor pole change type or motor primary voltage control type. But it will change to vector control type in order to increase it's reliability, riding comfort and decrease material cost. It is the conception of vector control type in order to increase it's reliability, riding comfort and decrease material cost. It is the conception of vector control that primary current of the induction motor be controlled independently with magnetizing current(field current of DC motor) and torque current(armature current of DC motor). In this paper, by analyzing the effect of the time constant variation of rotor of the induction motor on the slip frequency type indirect vector control, a drive system for the motor will be constructed using a fuzzy slip frequency type indirect vector controller with fuzzy control method for estimating the vector time constant in the slip frequency type indirect vector control. The goal of this study is to enabling even more efficient speed control by constructing on elevator driver based on the newly developed drive system.

• Journal of KIISE:Software and Applications
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• v.34 no.7
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• pp.603-615
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• 2007

Software changes for various kinds of reasons and they increase maintenance cost. Software metrics, as quantitative values about attributes of software, have been adopted for predicting maintenance cost and fault-proneness. This paper proposes relationship between some typical object-oriented metrics and software changes in industrial settings. We used seven metrics which are concerned with size, complexity coupling, inheritance and polymorphism, and collected data about the number of changes during the development of an Information system on .NET platform. Based on them, this paper proposes a model for predicting the number of changes from the object-oriented metrics using multiple regression analysis technique.