• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.1
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• pp.37-44
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• 2021

The information products dramatically reduce the production costs of vertically differentiated products. Information products are also more likely to be affected by network externalities. Thus the proliferation of digital products is increasing the interests in network externality and vertical product differentiation. In step with this trend, the impact of network externalities on price competition in vertically differentiated markets has been continuously studied. Existing studies related to this topic have assumed that network externalities increase consumers' willingness to pay per unit quality. The results show that higher quality products are affected more by network externality. However, network externality is essentially a concept affected by the size of the consumer, not a concept associated with quality. In this work, unlike previous studies, we present a new market model that reflects the essential definition of network externality. Based on the proposed market model, we derive both simultaneous and sequential Nash equilibria and analyze them numerically. The main results obtained from the analysis can be summarized as follows. First, network externalities primarily increase the demand for low-quality products and have a secondary impact on the demand for high-quality products. Second, the larger the quality difference between products, the more profitable they are. It also has been shown that sequential pricing methods are more advantageous in terms of revenue than simultaneous pricing method.

• Journal of Environmental Health Sciences
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• v.34 no.1
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• pp.108-115
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• 2008

This study was performed to investigate the current status, in Korea, of the production of asbestos containing products (ACPs) such as asbestos cement products, asbestos friction materials, asbestos joint sheets, asbestos textile products, and other asbestos-containing products from May 2 to July 30, 2007. The information on ACPs was obtained through written questionnaires from 16 of the 27 companies that produce ACPs in Korea. The production amounts of asbestos containing gaskets were 70 tons in 2004, 90 tons in 2005, and 55 tons in 2006 in 4 companies and that of asbestos friction materials were 435.5 tons in 2004, 540.4 tons in 2005, and 454.3s ton in 2006 in 10 companies. The type and number of ACPs were:- 19 asbestos cement products, produced by 2 companies; 47 asbestos friction materials produced by 18 companies; 12 asbestos joint sheets productes by 4 companies; 18 asbestos textile products from 3 companies, and 6 other asbestos products from 5 companies. The database of ACPs was constructed to include the products name, identification number, name of company, production year, composition, asbestos content (%), usage, specification, and a picture. The database will be used to efficiently identify ACPs and to avoid asbestos exposure in workers and the general population.

• Journal of the Korea Concrete Institute
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• v.11 no.3
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• pp.123-130
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• 1999

In a preceding study(1), the using method of garnet powder has been studies through the various investigation of basic material properties on garnet powder, industrial by-products generated in Yungju, Kyungpook. In this study, the various properties of concrete mixed with garnet powder are examined as following condition : Unit weight of water (170kg/㎥), water-binder ratio W/B (53, 55 and 58%), sand-aggregate ratio (S/A) (43, 45 and 48%), substitutional ratio of garnet powder of 0, 5, 10, 15 and 20%. Slump increased a little as the substitutional ratio of garnet increased. Air content decreased a little at the substitutional ratio of 10%. or more. Though there is a little difference in compressive strength according to the W/B and the substitutional ratio, compressive strength of concrete using garnet exceeded that of plain concrete a little in the range of the substitutional ration of 5 to 15%. Also, There is a similar tendency in the tensile and flexural strength. Therefore, the use of garnet powder with industrial by-products is expected to improve the workability and the strength of concrete.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.1
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• pp.78-84
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• 2002

This paper is a study for the computerization program of incoming and outgoing processes of a number of parts and a great amount of material for producing products in flood industry, which was required by a medium-sized company located at Cheon-An. The program consists of four databases, one main form, seventeen subforms, and eight report forms. Concretely speaking, the four databases are prepared for products, semi-products, material, and reports, and the seventeen subforms are those for current inventory, used quantity, safty stock, product specification, etc. With the program, users can be helped and save manpower, time and cost in incoming and outgoing processes of parts and material for producing products and in their real time operation and decision-making.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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• pp.168-177
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• 2009

The proliferation of the internet and electronic commerce has given the manufacturers the opportunity of direct marketing. This study analyzes the decision of manufacturers regarding whether to sell the products through independent sales company or to sell the products to the consumer directly. To do this, a new demand function is proposed and sub and super games are modeled and analyzed based on the demand function. By analyzing the Nash equilibria, it is shown that the manufacturers' decision of direct or indirect marketing not only depends on the competitiveness between the products but the absolute and relative marketing capabilities of the manufacturers. It is also shown that, in some cases, the manufactures have incentive to rise the competitiveness between the products to maximize the channel profit.

• Journal of the Korea Safety Management & Science
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• v.13 no.2
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• pp.115-127
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• 2011

The aim of this study was to develop a standard to estimate safety factors of corrugated fiberboard containers used for agricultural products. This study is limited to fresh agricultural products packaged in the corrugated fiberboard containers and further work needs to be done, but we believe the data and results obtained by this research will greatly help to set proper package design for boxes. Especially, safety factor would be practically helpful for researchers for future study and packaging users to save packaging costs.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.226-227
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• 2021

Various attempts are being made to reduce carbon emissions through recycling of industrial by-products in the construction materials industry to reduce carbon emissions, and cement substitutes such as blast furnace slag and fly ash are widely used. Although it is suggested that the use of industrial by-product aggregate is possible in 'Aggregate', the use case of industrial by-product aggregate is very rare in the actual field. In this study, as an industrial by-product, fine slag aggregate is used as fine aggregate among aggregates that can be used as aggregate for concrete, and coarse aggregate is used as a substitute for natural aggregate. WWe tried to suggest various ways to expand the use of industrial by-product aggregates.

• Proceedings of the Korean Society for Quality Management Conference
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• 2007.04a
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• pp.59-63
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• 2007

Customers have the various needs and personalities and try to get them. The behaviour of buying products, one of the highlight things, is the most general phenomenon of filling up their desires, and even these types are eventually personalized. Also there are various criteria for selecting it and also those are to be determined by the customers' own personalities. Mostly customers show the more attractive behaviours for those products which are more attractive to them, and for carefully buying them they use various paths. The criteria to buy the products are the mostly generalized things such as price, design, size, weight, trend, and so on, and it can be affected by the specifics of the products. But it is not definitely unimportant to consider the personality. Customers have the unusual personality for the product which is more attractive to them, and then for the unattractive, they only show the unclear criteria or specifics. The existing studies are focused on the product itself, and then they just show the results related to the specifics of the products, but it could be considered a case that the customers could think some products classified into the highly involvement products would be the lower involvement ones. Upon this, for same products if the customers show some differences of information(relating to the degree of involvement), I am going to figure it out by using AHP that what the criteria to buy is. In this study, with the computer products which are considered as the highly involvement products, I will select two groups showing the differences of awareness of the products, and then figure out the selecting criteria.

• Journal of Families and Better Life
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• v.21 no.1
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• pp.113-127
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• 2003

This paper aims to provide the basic data about the uses of agricultural products related to food, cloth and shelter in the late Joseon Dynasty by analysing$\ulcorner$Kyuhap-Chongseo$\lrcorner$(1809). The results of this study are as follows: 1. The agricultural products related to cloth, food and shelter were of 95 species total(horticultural crops 37.9%, industrial crops 22.1%, food crops 13.7%, floricultural crops 13.7%. and animal products 12.6%). 2. The agricultural products(24species) related to clothing were used for weaving, dyeing, laundering and starching textiles. 80 species of agricultural products were used as ingredients in about 140 dishes. As for shelter, the agricultural products(30species) were used for making stationaries. managing vessels and illumination, and building structures.

• International Journal of Reliability and Applications
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• v.7 no.1
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• pp.71-77
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• 2006

The market for second hand products has been growing for a variety of reasons (e.g., new products appearing at a faster rate and the expected life of products increasing due to rapid advances in technology). The demand for warranties for second-hand products has been growing along with the growth of the market for second-hand products. Warranty for new products (consumer durables, industrial and commercial, and specialized defense products) has received a lot of attention. In contrast, warranties for second-hand product have received very little attention. Often, dealers of second-hand product such as cars offer 2D-warranties (Year and Kilometers). The expected warranty cost associated with a second-hand product for 2D-Policies is a function of the age of the item and its usage (as it affects failures over the warranty period), the warranty terms and the servicing strategy used by the dealer. This paper deals with development of models for warranty cost analysis along with the decision on sale price and warranty cover for 2D-Warranty policies associated with sale of second-hand products.