• The Journal of Information Systems
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• v.31 no.3
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• pp.197-220
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• 2022

Purpose The purpose of this study is to identifies the demand pattern categorization of repair parts of Automotive After-sales Service(A/S) and proposes a demand prediction model for Auto repair parts using Long Short-Term Memory (LSTM) of artificial neural networks (ANN). The optimal parts inventory quantity prediction model is implemented by applying daily, weekly, and monthly the parts demand data to the LSTM model for the Lumpy demand which is irregularly in a specific period among repair parts of the Automotive A/S service. Design/methodology/approach This study classified the four demand pattern categorization with 2 years demand time-series data of repair parts according to the Average demand interval(ADI) and coefficient of variation (CV²) of demand size. Of the 16,295 parts in the A/S service shop studied, 96.5% had a Lumpy demand pattern that large quantities occurred at a specific period. lumpy demand pattern's repair parts in the last three years is predicted by applying them to the LSTM for daily, weekly, and monthly time-series data. as the model prediction performance evaluation index, MAPE, RMSE, and RMSLE that can measure the error between the predicted value and the actual value were used. Findings As a result of this study, Daily time-series data were excellently predicted as indicators with the lowest MAPE, RMSE, and RMSLE values, followed by Weekly and Monthly time-series data. This is due to the decrease in training data for Weekly and Monthly. even if the demand period is extended to get the training data, the prediction performance is still low due to the discontinuation of current vehicle models and the use of alternative parts that they are contributed to no more demand. Therefore, sufficient training data is important, but the selection of the prediction demand period is also a critical factor.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.1
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• pp.11-18
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• 2019

There is a growing demand for public rental housing since housing price increased rapidly and socially vulnerable people need more stable housing. The purpose of this study is to investigate housing evaluation (satisfaction), moving plan, and residential service according to the type of the public rental housing and the characteristics of the resident, and to suggest the development direction for comprehensive housing services including the community level. Data used for analysis in this study are from 2016 Seoul panel survey of public rental housing residents. A total of 3009 questionnaire from public rental households were collected in 2016 Seoul panel survey. In order to investigate housing requirements, we analyzed household characteristics, housing satisfaction, moving plans, welfare services, residential activities and community facilities, social environment. In this study, the difference of residential satisfaction, moving plan, and residential service according to the type of the public rental housing and the characteristics of the resident is analyzed to identify their housing demands. As a result, there were differences in residential satisfaction, moving plan, and residential service depending on type of public rental housing and characteristics of residents. Residents in public rental housing modified from the multi-family housing after purchase showed lower residential satisfaction, and higher intention for moving plan compared to residents living in other type of public rental housing. In the residential service, residents in permanent lease type have higher experience of housing service as well as demand on housing service. Especially single household, elderly household, female household, or household with handicapped person indicated higher demand for housing services.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.70-86
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• 2022

An autonomous demand-responsive bus with mobility-on-demand service is an innovative transport compensating for the disadvantages of an autonomous bus and a demand-responsive bus with mobility-on-demand service. However, less attention has been paid to the quantitative impact assessment of the autonomous demand-responsive bus due to the technological complexity of the autonomous demand-responsive bus. This study simulates autonomous demand-responsive bus trips by reinforcement learning on a microscopic traffic simulation to quantify the impact of the autonomous demand-responsive bus. The Chungju campus of the Korea National University of Transportation is selected as a testbed. Simulation results show that the introduction of the autonomous demand-responsive bus can reduce the wait time of passengers, average control delay, and increase the traffic speed compared to the results with fixed route bus service. This study contributes to the quantitative evaluation of the autonomous demand-responsive bus.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1B
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• pp.34-46
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• 2009

The remarkable growth of Korean telecommunication market has based on the introduction of competition as well as mobile technology like CDMA. It was well Down that such a conspicuous growth has been towed by mobile service rather than fixed telephone service. In telecommunications service the number of subscribers to mobile was over 40 millions in 2006 and also, while the traffic amount of fixed telephone has been more decreased, that of mobile, which already outnumbers the fixed, has been constantly increased and will be much more in future. It will accelerate the substitution of access and call demand of fixed service by mobile. This change of technology and demand does affect directly the market performance of telecommunications. And regulation has also an effect on market structure, which finally affects on market performance. In this paper we suppose the fixed and mobile telecommunications services are in a same industry. After reviewing the relations among the demand, cost, charge structure and revenue structure in the one fixed and mobile telecommunications market using the framework of an industrial structure analysis, we discuss the current issues of telecommunications regulation and implications for the future regulation.

• Korean Management Science Review
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• v.25 no.1
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• pp.29-41
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• 2008

In the mobile communication service market, this study represents an attempt to forecast the subscribers of the IMT-2000 service market using the questionnaire of experts which is the qualitative technique is used. In this study, by using the substitution model of next generations among products in order to analyze the IMT-2000 demand of service, a demand was predicted. And by estimating the market demand prospect in which it becomes the important factor of the IMT-2000 service diffusion according to each bandwidth frequency the politically necessary approaching direction about the frequency was presented. It will be able to become the important part to not only the business carrier but also the policy maker to examine a prospect toward the subscriber of the IMT-2000 service. As a result, the market demand was exposed to be most big when the SKT 800MHz, and the KTF 800(900)MHz were used as the additional frequency. And it was likely to reach to the IMT-2000 number of subscribers to about 35.750 thousand peoples in the future at 2015.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.195-200
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• 2010

This paper introduces a new mobile music service, private music on demand (PMOD), which is implemented by mobile DJ in wireless and wired networks. The newly introduced PMOD service is based on the concept that users can have music services at anytime and by any form they want. The mobile DJ implementing PMOD services, therefore, enables users to do more than simply listening music through networks.

• Journal of Information Processing Systems
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• v.19 no.2
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• pp.258-266
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• 2023

Aiming at the problems of poor customer satisfaction and poor accuracy of customer classification, this paper proposes a customer classification model based on speech recognition. First, this paper analyzes the temporal data characteristics of customer demand data, identifies the influencing factors of customer demand behavior, and determines the process of feature extraction of customer voice signals. Then, the emotional association rules of customer demands are designed, and the classification model of customer demands is constructed through cluster analysis. Next, the Euclidean distance method is used to preprocess customer behavior data. The fuzzy clustering characteristics of customer demands are obtained by the fuzzy clustering method. Finally, on the basis of naive Bayesian algorithm, a customer demand classification model based on speech recognition is completed. Experimental results show that the proposed method improves the accuracy of the customer demand classification to more than 80%, and improves customer satisfaction to more than 90%. It solves the problems of poor customer satisfaction and low customer classification accuracy of the existing classification methods, which have practical application value.

• Journal of Korean Library and Information Science Society
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• v.52 no.4
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• pp.229-253
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• 2021

The service strategy of the public library needs to be established based on the users who are the actual beneficiaries of the services, including the perspective of changes in the social environment. This study investigated and analyzed the users' perceptions of the library functions and services currently provided and the demand for future services, targeting public library users in the Busan area. The data were collected through a questionnaire, and the respondents were 733 public library users in Busan. The main result is that first, the role and function of the public library that Busan users consider most important was still in material collection and provision. Second, in the information service type, the demand for cultural/lifelong learning program service was the highest, and in the service program, the demand for new IT technology experience and education was the highest. Third, as a result of ISA analysis of information service type, material provision service and information literacy education service were types to be maintained, and reading related service was type to be managed intensively. Fourth, in the analysis of service demand by age, those aged 41 to 50 years old were the generation with the highest demand in all types except for the information literacy education service type, and the demand for information literacy education was the highest among the elderly generation over 61 years old. And the user group in the western part of Busan was higher than the user group in other regions in demand for almost all service types. The results of this study can be used as basic data when establishing strategies to optimize community public library services for users.

• International journal of advanced smart convergence
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• v.1 no.2
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• pp.59-63
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• 2012

The mVoIP service is the technology which focuses on the wireless data service as the IP network having the transmission rate of 100 Mbps classes on the high-speed middle of movement through the WiFi, WiBro and 3G mobile radio communication network, and etc. and is developed. Since 2010, the mVoIP (mobile VoIP) service shows the rapid growth due to 4G-LTE service seriously disclosed from July with the Smart phone and 2,011 it begins to be rapidly popularized. In this research, additionally the mVoIP service industry activation plan is presented with the trends of technology development including the chip-set/module/terminal, etc. based upon local and foreign market trend searchlight through the market demand analysis. The mVoIP service downloads App to the mobile apparatus and or can provide the service as the software through the WiFi network. Therefore, the change which is large in the products development aspect is to be have no. Expected to is being provided as the added service in the case of 4G-LTE as a matter of course, the service deployment where it is based on the market principle and demand needs is needed.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.274-277
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• 2008

Demand analysis plays a key roles in helping decision making in all fields of production activities. In order to analyze the demand of the client, items on the preference motivation for CM service has to be formalized, but it is difficult to establish. The purpose of this study is to present items of demand analysis for CM Clients. For this, the factors affecting purchase of CM service for CM Clients are analysed through literature review in other various areas about intend to purchase. Through this, increase the importance of the CM demand analysis and understand the service demand, the growth of the CM market, important foundation.