• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.60
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• pp.11-22
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• 2000

The main objective of this research is to analyze an order point and an order quantity of a distribution center and each branch to attain a target service level in multi-level inventory distribution system. In case of product item, we use the item with low volume of average monthly demand. Under the continuous review method, the distribution center places a particular order quantity to an outside supplier whenever the level of inventory reaches an order point, and receives the order quantity after elapsing a certain lead time. Also, each branch places an order quantity to the distribution center whenever the level of inventory reaches an order point, and receives the quantity after elapsing a particular lead time. When an out of stock condition occurs, we assume that the item is backordered. For considering more realistic situations, we use generic type of probability distribution of lead times. In the variable lead time model, the actually achieved service level is estimated as the expected service level. Therefore, this study focuses on the analysis of deciding the optimal order point and order quantity to achieve a target service level at each depot as a expected service level, while the system-wide inventory level is minimized. In addition, we analyze the order level as a maximum level of inventory to suggest more efficient way to develop the low demand item model.

• Journal of the Korea Safety Management & Science
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• v.21 no.1
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• pp.9-16
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• 2019

Logistics companies are worrying about securing of differential competitiveness so as to be competitive companies in keen logistics market. The ground is how users are satisfied by sell-established service system to respond not only economic feasibility of logistics costs but also diversity and advancement of logistics needs. The competitiveness of logistics companies is also caused by customer satisfaction of service and only companies finding and satisfying customer needs continuously may be more competitive. For the competitiveness, it's the most important to analyze demands of current and potential customers and their pursuing value properly. Therefore, this researcher grasped PSL for online logistics service users with 5-point Likert-scale and quality-level decision method that consider the weighted value based on Kano model, measured customer's potential Demand for service through PCDI, and suggested methodology for deciding the priority of the improvement with loss function of Taguchi.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.3
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• pp.13-20
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• 2019

This study focused on the generational change of elderly people in the future based on the changes of aging background and household structure. After 2025, when the growth rate of aging rapidly becomes prominent, the generation born before 1961, the baby boomers who were in their youth after the country's liberation, will replace the current elderly generation. This means that the characteristics and values of living of the elderly will change and not pass on to the future, and that the demand for housing will also be different. The purpose of this study is to predict the future elderly housing demand and to find out the issues of housing support for elderly people and necessary institutional support items. For this purpose, the preliminary elderly people are surveyed and analyzed for their present housing condition, perception of old age, housing plan, welfare facilities and demand for living services. The results of this study are meaningful in laying the groundwork for predicting the demand for housing and living support of the elderly in the future and proposing suggestions and preparing related systems.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.441-445
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• 2004

In this paper, we deal with an inventory model of a multi-stage, serial supply chain system where a single product type and nonstationary customer demand pattern are considered. The retailer and suppliers place their orders according to an echelon-stock based replenishment control policy. We assume that the suppliers can access online information on the demand history and use this information when making their replenishment decisions. Using a reinforcement learning technique, the inventory control parameters are designed to adaptively change as the customer demand pattern is altered, in order to maintain a given target service level. Through a simulation based experiment, we verified that our approach is good for maintaining the target service level.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.721-729
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• 2009

Recently, there has been growing necessity to estimate the future travel demand of high speed train because the circumstance of high speed train service is rapidly changing with the launching of 2011 second stage of Gyeongbu high speed railway(Dongdaegu-Busan) and the completion of 2014 first stage of Honam high speed railway(Yongsan-Gwangju), etc. This study was designed to estimate future travel demand by analyzing the transport performance and train service characteristics of Gyeongbu and Honam line. This study presents the maximum load section and the changed future travel demand, which will be applied to establish a train operation plan.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.3
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• pp.149-159
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• 2006

To provide on-demand video streaming services through the network, video objects with both high and low client request rates should be served efficiently. In this paper, we propose a dynamic on-demand streaming approach for providing services efficiently regardless of the client request rate. This approach can maintain QoS by transitioning the service scheme according to the request rate. The server provides services by the Heuristic broadcasting approach when the client request rate is low and by Striping broadcast, one of many Periodic broadcast approaches, when the client request rate is high. The server knows the variations of client request rates by the number of service channels and decides the transition to more efficient service schemes on its own. We simulated this scheme transition with various client request intervals and traces from a company providing streaming services. The results show that the performance of our approach is reasonable.

• Journal of Information Science Theory and Practice
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• v.10 no.spc
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• pp.1-11
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• 2022

As data-based research activities and outcomes increase and ontact or non-face-to-face activities become common, the demand for easy utilization of resources, tools, functions, and easily accessible information required for research in the R&D sector has increased accordingly. With the rapid increase in the demand for collaborative research based on online platforms, research support institutions strive to provide venues for research activities that merge various information and functions. ScienceON, an integrated science & technology (S&T) knowledge infrastructure service developed and operated by the Korea Institute of S&T Information (KISTI), supports open collaboration by connecting and merging all the information, functions, and infrastructure required for research activities. This paper describes the online research activity support tool provided by ScienceON and the remarkable results achieved through this activity. Specifically, the excellent creation of the following flow of meta-material research activities in the ontact space is elucidated. First, the papers required for a meta-material analysis are retrieved, virtual simulation is conducted with the experimental data extracted from the papers, and research data are accumulated. ScienceON's tools for supporting ontact research activity will play a role as an important service in the era of digital transformation and open science.

• Journal of Information Processing Systems
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• v.17 no.1
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• pp.191-202
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• 2021

In an Internet of Things (IoT)-configured system, each device executes on-chip software. Recent IoT devices require fast execution time of complex services, such as analyzing a large amount of data, while maintaining low-power computation. As service complexity increases, the service requires high-performance computing and more space for embedded space. However, the low performance of IoT edge devices and their small memory size can hinder the complex and diverse operations of IoT services. In this paper, we propose a remote on-demand software code execution unit using the cloudification of on-chip code memory to accelerate the program execution of an IoT edge device with a low-performance processor. We propose a simulation approach to distribute remote code executed on the server side and on the edge side according to the program's computational and communicational needs. Our on-demand remote code execution unit simulation platform, which includes an instruction set simulator based on 16-bit ARM Thumb instruction set architecture, successfully emulates the architectural behavior of on-chip flash memory, enabling embedded devices to accelerate and execute software using remote execution code in the IoT environment.

• Journal of Urban Science
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• v.7 no.2
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• pp.1-9
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• 2018

In this study, Analysis of DRT model and contribustion based on the case of local governments adopting the Demand Responsive Transit(DRT) in order to provide transportation in public transportation service weak area. Based on the case of Yeoju Area, the contribution of the DRT was analyzed. The DRT model was established as a fixed and call type model with taxi and bus transportation. Based on the results of the happy taxi service in Yeoju Area in 2016, the contribution of DRT was analyzed. According to the happy taxi performance of Yeoju city, it was introduced to 27 villages, and operated 4,188 times. And 9,111 people used it and Yeoju Area supported about 53 million Won. The contribution of local governments was analyzed in terms of local government, users, and social aspects. On local government aspects, we analyzed the budget cuts and complaints resolution. On the user aspects, we analyzed waiting time reduction, walking time reduction, travel time reduction, comfort, punctuality, and stability. On social aspects, we analyzed taxi and regional economy activation, and convenience of mobility.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.1
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• pp.118-127
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• 2018

Recently, service quality must reflect several demands of customers who show rapid and various changes so as to be compared with the past. So, objective and rapid measuring methods for service quality are necessary. For them, first of all, service company must calculate their standard of service quality accurately by measuring service quality exactly. Kano classified the degree of influence that is the degree of correspondence of the quality attributes of products and services to the subjective satisfaction of customers. As a result, the types of qualities are classified as attractive, must be, one dimensional, and indifference attributes. They have been widely used quality attributes in various industrial fields up to now. However, Kano model has a limit that it ignores the characters of the next frequent numbers even though there are not much gap comparing to the most frequent number in the questionnaire answers. The limit is attributed to the character of Kano model that the most frequent number is accepted as the only quality character. Timko calculated the customer satisfaction coefficient by using Kano's method and studied the differences in quality character by classifying the quality characteristics in a graphical way through the relationship between the satisfaction and the dissatisfaction coefficient. In this study, we used the quality level determination method of the 7-point Likert scale, which takes the weight into account, to complement the deficiencies of the existing Kano model. We also developed and applied a Potential Satisfaction Level (P) and Potential Customer Demand Improvement (PCDI) Index to present a new approach to the determination of service quality attributes. To measure the level of potential service satisfaction and to understand the degree of improvement, we collected specimens of 51 participants who has been trained in the National Strategy Business Training Program, which has been managed by government agent, and analyzed the results.