• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.1
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• pp.1-13
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• 2007

Nowadays, ubiquitous computing services begin to be suggested from a few domains such as supply chain, logistics, and location-based services. However, to what extent the services will be successful is hard to be estimated, mainly because a sophisticated service evaluation method focusing on the ubiquitous computing perspective has not been supplied. Hence, this paper alms to build a model to assess the quality of ubiquitous computing service. To do so, an amended model, Ubi-SERVQUAL, is applied to assess the service quality mentioned in ubiquitous computing scenarios. According to the Ubi-SERVQUAL, we found that an actual service with higher quality should consider reliability. responsiveness, assurance and empathy in order to increase customer satisfaction, computer system's intimacy with users and trust.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.1-10
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• 2009

Inventory Management has become a very important issue in supply chain management, because inventories may be used as a means to accomplish the certain strategic goals in company decisions. RFID(radio frequency identification) technology is used to help manage inventories. It is known that the ideal control of inventories is to replenish item by item. This paper points out several misinterpretations from the Wal-mart report presented in '07 Seoul Forum and suggests the new direction of RFID application. In this paper we consider RFID as not 'identification technology' but 'information technology.' The 'RF-Kanban' suggested here is adopted from the'Kanban'concept of TPS(Toyota Production System). The RF-Kanban system shows the easier control for replenishing various items in boxes. Lots of inventories can be reduced through RF-Kanban System. This work develops the protocol of RF-Kanban and introduces the case study for easier understanding.

• Management Science and Financial Engineering
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• v.17 no.2
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• pp.1-21
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• 2011

This paper considers an integrated inventory-distribution system with a fleet of heterogeneous vehicles employed where a single warehouse distributes a single type of products to many spatially distributed retailers to satisfy their dynamic demands. The problem is to determine order planning at the warehouse, and also vehicle schedules and delivery quantities for the retailers with the objective of minimizing the sum of ordering cost at the warehouse, inventory holding cost at both the warehouse and retailers, and transportation cost. For the problem, we give a Mixed Integer Programming formulation and develop a Lagrangean heuristic procedure for computing lower and upper bounds on the optimal solution value. The Lagrangean dual problem of finding the best Lagrangrean lower bound is solved by subgradient optimization. Computational experiments on randomly generated test problems showed that the suggested algorithm gives relatively good solutions in a reasonable amount of computation time.

• Journal of Korean Society for Quality Management
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• v.29 no.1
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• pp.113-127
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• 2001

Skip-lot sampling plans for lot-by-lot inspection are more desirable than the continuous sampling plans for units in modern mass production system under the condition of the submitted product is good. Perry(1973a, 1973b) extended the Dodge(1955)′s skip-lot sampling plans to single and two-level skip-lot sampling plans and Parker & Kessler (1981) modified Perry(1973a)′s plans so that a sample of size one is taken from every lot skipped during the skipping mode. In this paper, Perry(1973b)′s two-level skip-lot sampling plans are modified by applying Parker & Kessler′s plan, designated as MTSkSP1, MTSkSP2, MTSkSP3. Operating characteristic(OC) functions, average sample numbers(ASN) and average outgoing qualities(AOQ) for the proposed plans are derived using Markov chain properties and compared each other and Perry′s plans. The proposed plans not only reduce the ASN but also avoid the danger skipping lots entirely when the lots are produced during sudden "out-of-control".

• Journal of East Asia Management
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• v.2 no.1
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• pp.23-48
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• 2021

The consumer is living in the frame which is called a city and is leading life through "the purchase act". As for there not being "the purchase act", our life doesn't stand up. It is possible to say that the retail trade it therefore occupies the mailbox which is important in the urban function. However, as for former research, the functional model about the retail trade in the city leaned to the gross income of the customer development degree of each retail store and the retail trade in the city and the overall show of the model of "the role of the retail trade in the city" wasn't done. Therefore, at this article, it focuses on the retail business status, the chain store which has a multitude ready in the retail trade, and it has a purpose of seizing out boiling and considering and making a new hypothesis about how the retail trade which is one of the urban functions contributes to the city.

• Korean Management Science Review
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• v.28 no.3
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• pp.1-13
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• 2011

Hub-and-spoke transportation network is a powerful and useful network structure that takes full advantage of economies of scale on routes between hubs. In recent studies, the network structure is extended to hybrid hub-andspoke that allows direct transportation between spokes. In this study, we considered more extended network structure which is called hybrid multiple hub-and-spoke that has multiple hubs and allows direct transportation between spokes. We developed a mathematical optimization model for automotive service parts transportation planning under hybrid multiple hub-and-spoke network structure. The model suggests a long-term transportation route planning and a short-term vehicle assignment planning. The model is verified by simulation and validated in real world application to Hyundai Mobis automotive service parts transportation planning. From the simulation result, the model reduced the transportation cost about 24.7%, the total distance about 6.8% and the CO2 emissions about 8.8%. In real world application for 6 months from July to December 2010, the model reduced the transportation cost about 9.1% by changing the long-term transportation route without daily vehicle assignment planning.

• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.149-168
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• 2015

It is expected that the temperature in Pyeongyang will be similar to that ($16.6^{\circ}C$) in Seogwipo in the late 21st century, and most of South Korea will enter the subtropical climate due to climate change. Change in the precipitation pattern like the range of fluctuation caused by climate change will lead to expanded uncertainty in securing reliable water supply, along with a serious impact on demands for living and industrial water due to change in the volume and period of river outflow. As industrial water for production activities is estimated based on the contract quantity, it is difficult to apply rationalization of water usage and incentives in water recycling. Therefore many companies are making efforts in complying with the effluent standard while spending few resources on such rationalization and recycling. This study researched water risk management over 115 Korean companies by 28 questions in 4 categories. Through the research, this study aims to understand water risk management levels and seek response plans.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.183-191
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• 2013

After the Uruguay Round, Korean agriculture industry has been protected and reared with government grants. However, until now there has been very minimal development to establish a solid export industry which can make the most of the trade agreements in place. There has been much research on ways to expand agricultural exports in order to respond properly to this ever changing environment and sustainable agricultural industry. As all other export industries, an efficient logistics network is paramount in order to allow the agricultural industry to respond to changes in demand and penetrate global markets. The lack of systematic logistics activities such as packaging, transportation, unloading, storage, and information transfer in farms has been a major factor in the inefficiency of the agricultural industry resulting in minimal development. From this perspective, 3PL was proposed and applied as a way to build on the streamlining of export of agricultural logistics system. The Agri 3PL is considered as an efficient agricultural exports method as a new concept connecting producers with exporters.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.1
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• pp.43-56
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• 2023

The aviation industry has continued to grow despite the influence of external environmental factors such as SARS and MERS. However, this growth has led to a sharp decrease in air traffic and a crisis of flight suspension due to the collapse of the global value chain and the decline of the world economy as the World Health Organization (WHO) declared a COVID-19 pandemic. Due to the decrease in the number of international flights, aviation workers such as pilots and cabin crew were exposed to high psychological stress and fatigue, such as large-scale layoffs, job instability, decrease in income, and increased risk of infection during. Recently, the international community has eased immigration restrictions through quarantine activities, and airlines are taking a step further to recover existing air demand. However, during the crisis period, a significant number of professional workers have been turned off or fired, and the physical and mental fatigue of those who can perform their duties is increasing. Therefore, this paper intends to examine the direction of policy improvement and the identification of problems in aviation safety and fatigue management after the pandemic.

• The Korean Journal of Food And Nutrition
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• v.31 no.5
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• pp.616-630
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• 2018

This study analyzed the current status of registered patents related to food tech in Korea and Japan. Using the patent information search services of Korean and Japanese Patent Offices, patents registered during the past 10 years from January 1, 2005 to December 31, 2015 were searched with the following key words/phrases: "food or meal or diet" and "program or information system". A total of 669 patents (539 for Korea and 130 for Japan) were finally selected and analyzed. Based on Porter's value chain theory, the patents were categorized into three dimensions related to "manufacturing/processing/distribution", "sales & marketing", and "consumer support". The results showed that in Korea, 41.7% of the total patents were related to sales & marketing followed by consumer support (37.3%) and manufacturing/processing/distribution (21.0%). In Japan, patents related to consumer support accounted for 56.2% followed by manufacturing/processing/distribution (32.3%), and sales & marketing (11.5%). In the area of manufacturing/processing/distribution, "food quality management system" in Korea, and "food manufacturing and processing management system" and "food safety control and hazard analysis system" in Japan tended to show a significantly higher proportion of patents registered (p<.05). Under sales & marketing, patents in the categories of "food purchase and delivery service system" in Korea and "restaurant information sharing system" in Japan tended to be more frequently registered (p<.05). Finally, in the area of consumer support, "kitchen facility and cooking device control system" in Korea and "menu and nutrition management system" in Japan tended to account for a significantly higher proportion of patents registered (p<.001). The results are expected to provide useful insights into the development of new patents and markets for food tech in the future.