• Journal of the Korean Operations Research and Management Science Society
• /
• v.29 no.1
• /
• pp.101-112
• /
• 2004

Customer satisfaction level is usually measured in terms of price, qualify, customization, after-sale-service, product variety etc. Each firm sets up a distinctive production/marketing strategy to gain competitive advantage by Prioritizing the customer satisfaction measures. The market differentiation strategy directly results in supply chain performance such as lead time, inventory, customer fill rate and market share. Product proliferation desirable in customization sense often conflicts the economies of scale effect in production side. This paper focuses the relationship between product variety and market share. Specifically, we investigate how introduction of new product affects the current market share, i.e., formation of customer preference and provide some insight into the optimal range of product variety.

• Proceedings of the KWS Conference
• /
• 2007.11a
• /
• pp.306-309
• /
• 2007

It shows not only positive effect with fan as a way of improving condition in workplace but also shows air supply, ventilation condition in welding site with CFD analyzation. Also when the wind blew to the front side by a fan, the welding Hume significantly reduced, As this was examined as CFD and was gone through enough exhaustion to become streamline flow laminar, the toxic materials will be reduced. The improvement of welding work and education are investigated to be more significant factors than wearing protective equipments and setting safety tools to prevent welding works from welding fume exposure.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.11a
• /
• pp.165.2-165.2
• /
• 2011

Flow with suction to water turbine must be in stable state at small hydraulic power plant. But because of water level fluctuation and water gate effect according to irregular supply of cooling water, it would happen to produce bubble and vortex and finally lead to problems in power-plant system. With utilizing the concept design of double size gate, surface water overflowed the overhead of gate for stable flow at suction. We developed the overflow condition and analyzed the design factor with existed one such as water level(overflow amount) and overhead of water gate(overflow figure). Flow test and CFD simulation say that flow have stable state around suction and 20% of wave reduction effect at surface layer after surface water overflow.

• Proceedings of the KIEE Conference
• /
• 1997.07c
• /
• pp.1083-1087
• /
• 1997

Every effort is now being exerted in industrialized and developing countries to reduce emission of greenhouse gases from electric power sector. In this paper, we provide supply-side resource mix strategies in the long-term generation expansion planning under the expected greenhouse gas regulations. Under the environmental regulations, we explore the least-cost generation expansion plan of Korea and determine the composition of future resource mixes. Our analysis is performed on the basis of the revised WASP package which can evaluate emission of carbon dioxide from each power plant. The evaluation process of carbon dioxide emissions, which can consider the efficiency and operating conditions of each generator simultaneously, has been incorporated into the probabilistic production cost simulation module of WASP.

• Journal of Communications and Networks
• /
• v.14 no.6
• /
• pp.672-681
• /
• 2012

A potential breakthrough of the electrification of the vehicle fleet will incur a steep rise in the load on the electrical power grid. To avoid huge grid investments, coordinated charging of those vehicles is a must. In this paper, we assess algorithms to schedule charging of plug-in (hybrid) electric vehicles as to minimize the additional peak load they might cause. We first introduce two approaches, one based on a classical optimization approach using quadratic programming, and a second one, market based coordination, which is a multi-agent system that uses bidding on a virtual market to reach an equilibrium price that matches demand and supply. We benchmark these two methods against each other, as well as to a baseline scenario of uncontrolled charging. Our simulation results covering a residential area with 63 households show that controlled charging reduces peak load, load variability, and deviations from the nominal grid voltage.

• Proceedings of the SAREK Conference
• /
• 2005.11a
• /
• pp.235-240
• /
• 2005

Recently urban utility plants in urban areas of Korea, such as energy supply systems, municipal waste incineration systems, sewage treatment systems and so on, have caused some critical troubles, for instance the insensitive response to the seasonal or daily variation of loads, the low system efficiency and inefficient use of energy because of the large-scale system located a great distance. Therefor the design method of optimal integrated system model of various urban utility plants proposed in this study suitably to the present situation of Korea. Also, the effect analysis for the introduction of compound utility plants was studied for a new town model on a 60,000 persons scale. As the results we found that the complex plant was superior to individual urban utility plant in side of the initial investment expenses, the operating cost and other reasons.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.237-242
• /
• 2008

DSM(Demand Side Management) is reducing the load of energy supply utility through energy conservation and energy load distribution. This kind of program is necessary especially to our country which import above 97% of energy source. But the effectiveness of this kind program is not verified well even though our country is executing the various DSM programs. This study suggests M&V(Monitoring & Verification) guideline for DSM programs which are executing in Korea and shows the results which applied to verification of DSM programs.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.32 no.3
• /
• pp.81-96
• /
• 2007

This paper analyses the Korean information and communication technology supply side across the economy using 1995, 2000 and 2003 input-output tables. Input-output analysis considers inter-industry relations in an economy, depicting how the output of one industry goes to another industry where it serves as an input, and thereby makes one industry dependent on another both as customer of output and as supplier of Inputs. It can be evaluated that the recent growth of Korean ICT sector has come from the development of communication service and equipment industry and software industry. Although the high performance and positive revealed comparative advantages in ICT manufacturing sector, the value added and employment in that sector are not satisfactory. It may reflect in part high portion of imported intermediate goods in ICT manufacturing. However, it is fortunate that ICT services, which accounted for relatively high value added, induce the development of ICT manufacturing and follow strong export performance. Moreover, it is expected that the software sector with high value added and employment will be a major driver of ICT growth.

• The Korean Journal of Pain
• /
• v.6 no.2
• /
• pp.255-257
• /
• 1993

Shoulder Hand Syndrome is used to describe painful disabilities of the upper extremity due to disturbances of sympathetic nerve supply. A 72 year old male developed hemiplegia on left side on the 5 days after open heart surgery of aortic valve replacement. Three months later, the patient complained of severe pain in the left upper extremity involving shoulder. The left hand showed swelling and flaccid paralysis. Thereafter the left stellate garglion block with 10 ml of l% lidocaine produced prompt pain relief. Thereafter the patient received 94 stellate ganglion block during 7 months which produced permanent remission of pain throughout a 1 year follow period. We recommand sympathetic block for of Shoulder Hand Syndrome following hemiplegia.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.18 no.4
• /
• pp.4265-4273
• /
• 1976

1. Fine aggregates of concrete are very important for the construction works and construction cost determination. Most of fine aggregates are from the river sand, but the amount of storage in the river side is steadily decreasing due to continuous construction works. Therefore, another source of fine aggregates is needed to meet increasied demand of sand. 2. Beach sand is a possible source of fine aggregates. But rust of steel bar is caused by CL-chemical of beach sand. Therefore, desalinization of beach sand is requested to get durable reinforced concrete. Economical methods of desalinization are as follows. (a) Flooding and drainage method. (b) Washing of beach sand with water supply and mixing. (c) Spreading of beach sand on the land and leaching by rain water for a few month. 3. Hardening of concrete with beach sand is accelerated due to salt, Thus early stage strength increase leads to make cracks. Also later stage strength decreases and durability becomes worse. By using appropriate admixture, the quality of concrete can be improved.