• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.284-286
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• 2003

The low load power factor causes various problems such as the Increase of the power loss and the voltage instability. The demand of reactive power increases continuously with the growth of active power and the restructuring of electric power companies makes the integrated management of ractive power troublesome, from which the systematic control of load power factor is required. In this paper, the load power factor sensitivity of the generation cost and integrated costs are used for determining the locations and capacities of reactive power compensation devices effectively and for enhancing the load power factor appropriately. It is shown through the application to a small-scale power system that the system power factor can be enhanced effectively and appropriately using the load power factor sensitivity and integrated costs.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1705-1711
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• 2017

This paper analyzes the impact of DRA (Demand Response Aggregator) on market power when competing with power generation companies (Gencos) in the electricity market. If congestion occurs in the transmission line, the strategic choice of the power generation company increases exercise of market power. DRA's strategic reduction of power load impacts the strategy of Gencos, which in turn affects the outcome of the load reduction. As the strategy of Gencos changes according to the location of the congested transmission line, the impact on the market depends on the relative location of the congested line and the DRA.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.304-308
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• 2008

The standardization for Seamless IP Mobility between heterogeneous networks is being progressed according to each specific purpose of the organizations such as ITU-T (International Telecommunications Union - Telecommunication), 3GPP(3rd Generation Partnership Project), IETF(Internet Engineering Task Force), and IEEE(Institute of Electrical and Electronics Engineers). [1] Specially VCC (Voice Call Continuity) for seamless voice continuity between heterogeneous networks using IMS (IP Multimedia Subsystem) of the next generation platform is being introduced into a few companies, and also MIH (Media Independent Handover) and MIP (Mobile IP) for IP mobility between heterogeneous networks are being customized by their internal situation. This article describes the idea to support IP Mobility between heterogeneous networks in the network which IMS platform is deployed and only supports the mobility for the voice by the type of AS (Application Server).

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.69-81
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• 2021

While the fifth generation (5G) and beyond 5G (B5G) mobile communication networks are being rolled over the globe, several world-wide companies have already started to prepare the sixth generation (6G). Such 6G mobile networks targets ultra-reliable low-latency communication (URLLC). In this paper, we challenge to reduce the inherent latency of existing non-orthogonal multiple access (NOMA) in 5G networks of massive connectivity. First, we propose the novel unipodal binary pulse amplitude modulation (2PAM) NOMA, especially without SIC, which greatly reduce the latency in existing NOMA. Then, the achievable data rates for the unipodal 2PAM NOMA are derived. It is shown that for unequal gain channels, the sum rate of the unipodal 2PAM NOMA is comparable to that of the standard 2PAM NOMA, whereas for equal gain channels, the sum rate of the unipodal 2PAM NOMA is superior to that of the standard 2PAM NOMA. In result, the unipodal 2PAM could be a promising modulation scheme for NOMA systems toward 6G.

• Journal of the Korea Fashion and Costume Design Association
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• v.24 no.3
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• pp.111-125
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• 2022

Recently, the MZ generation has been leading overall fashion trends, and fashion companies focus on design, marketing, and new products targeting the MZ generation. However, it is expected that a fit problem may occur if the M and Z generations are combined when producing clothing. Therefore, this study aims to analyze the differences between the two groups by comparing the body size according to the classification of the M and Z generations. In addition, this study analyzes whether the body shape of the MZ generation is different from the past generations and analyzes major changes in body size for clothing manufacturing through graphical visualization. As for the research method, a t-test was conducted to verify the significant difference between the measurements for each age group. Generation M was defined as those who are 27-39 years old, and Generation Z was defined as those who are 20-26 years old. In order to examine the changes in body measurements according to the measurement year, the 7th Size Korea and 8th Size Korea data were analyzed. In order to examine the visual changes according to the measurement year and age group, major measurements of clothing construction were analyzed. As a result, it was found that Generation M had a significantly higher height item than Generation Z. Also, in terms of circumference, width, and thickness, Generation M was larger than Generation Z. But the size of the bra cup was larger in Generation Z than Generation M. As a result of analyzing the body size changes, in the height item, the 8th Size Korea measurements were found to be significantly higher in shoulder height and navel level waist height. In the length and circumference items, the 8th Size Korea measurements were larger than the 7th. In the width, thickness, and other items, the 8th measurements were larger than the 7th.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.472-475
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• 2005

Genenrally, biogas contained methane contents of $40-75\%$, was made in anaerobic compost facilities, landfill site, etc. And it is very useful for gas engine as a fuel. So, many imported biogas engines for electrical generation, are installed and operating now at landfill sites and anaerobic compost facilites. And KIMM has studied on and developed biogas engines with the aids of engine maker and parts companies for several years. Some results are shown here.

• Journal of Welding and Joining
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• v.20 no.3
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• pp.46-53
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• 2002

The expolitation of substitute material and new manufacturing technology of the automobile body panel for next generation cars have been steadily professed by advanced automobile companies. High strength steel of TRIP (Transformation of Induced Plasticity) type is developed in response to demands about crash safety and high strength of automobile. In this study, basic technologies can fix up problems occurring on the mass production and applied to the other forming methods will be prepared through rasping a property of TRIP material.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.3-6
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• 2004

Industrial gas separation by membranes began in 1980 with the introduction of hollow-fiber polysulfone membrane systems by Permea, at that time a division of Monsanto. This first application was the recovery of hydrogen from ammonia reactor purge gas and was soon followed by the generation of nitrogen from air. Today, membrane gas separation ranks second behind cryogenic distillation in terms of nitrogen production, and this application has drawn the industrial gas companies into the membrane field.(omitted)

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.4
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• pp.149-163
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• 2023

The policy of promoting innovation clusters aims to enhance the competitiveness of industries by strengthening the linkages between industry sectors and research sectors in specific regions. In Korea, after the concept of innovation clusters was introduced by the OECD in 1997, Korean government actively pursued policies based on this concept in the fields of industry, region, and science and technology. Previous policies and research on the activation of innovation clusters have tended to focus on the exchange and collaboration among members. However, this study focused on enhancing the competitiveness of industries and regions, in other words, strengthening the competitiveness of companies, which is the fundamental reason for fostering innovative clusters. Accordingly, this study aimed to analyze the impact of factors activating innovation clusters on the business performance of SMEs located in the Daedeok Innopolis. To achieve this, based on the essential concept of innovation clusters such as industrial agglomeration factors, networking factors, innovation generation factors, the study derived factors for activating innovation clusters and verified hypotheses using the survey results of 175 companies. Among the factors activating innovation clusters, industrial agglomeration and innovation generation were found to have a positive impact on the business performance of companies. However, networking factors were analyzed to have no significant influence on the business performance of companies. This study differentiates itself by addressing the factors for activating innovation clusters through empirical analysis, unlike previous case-based studies. Furthermore, considering the difference between intuitive judgments on networking factors in innovation clusters and their actual impact on business performance, the study raised the practical significance of conducting a comprehensive examination from various perspectives, such as the socially and culturally embedded structures in the region, the characteristics of specialized industries, and the needs of cluster members, to develop more effective policies for innovation clusters.

• Journal of the Korean Operations Research and Management Science Society
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• v.12 no.1
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• pp.157-157
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• 1987

Hydro-electric power generation from multi-purpose dams has been playing important roles in the electric power supply network in Korea. Although the total share of hydro power in national electricity supply now becomes very small, the peak-shaving and frequency control capability of hydro power helps the power company enormously in maintaining the quality of power. But since the company that builds and operates the multi-purpose dams in Korea has to sell all the electricity produced to the monopolistic utility, there have been various problems in justifying the investment, designing pricing mechanism, and controlling operations of the power plants. In addition, economic evaluation of the hydro power has been distorted by a variety of reasons and hence it has been very difficult to encourage effective development and utilization of national water resources. To make the problem worse, both parties are public companies with X-inefficiency problems. Thus, changing environment requires to reengineer the system that governs hydro power generation. We address the problems of Korean hydro-electric power generation system in four areas: the investment justification process, the operations decison right of the hydro power plants, the pricing of the purchased-power, and the negotiation of contract revision. Then we propose improvement directions of new hydro-electric power system in view of static and dynamic efficiency, X-inefficiency and equity.