• Journal of Industrial Technology
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• v.23 no.A
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• pp.29-33
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• 2003

This paper proposed methods of filament preheating to extend a fluorescent lamp life. The ballast for the fluorescent lamp can be classified into two main groups magnetics and electronics. The electronic ballast is lighter and smaller than the magnetic ballast and it can dim up and down. There are two ways to start the fluorescent lamp in the electronic ballast: rapid start and instant start. Also there are two methods of the driving inverter self excited oscillation and force excited oscillation. The rapid starting is different from the instant starting in that the rapid start is preheating the filament before the steady state. If there is a preheating process before the lamp ignition, the life of the fluorescent lamp can be increased. This paper presented the preheating methods for self excited oscillating system and force excited oscillating system.

• International Journal of Aerospace System Engineering
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• v.2 no.2
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• pp.62-66
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• 2015

The starting processes of the Ludwieg tube hypersonic quiet tunnel plays very important role in the achievement of the quiet flow in the test section, which could affect the confidence coefficient of the data in the hypersonic transition experimental investigations. Thus, numerical analysis on that processes could help to understanding the running mode of the Ludwieg tube quiet tunnel and the propagation principle of the expansion wave series. To verify our computational method, the same parameter of the BAM6QT (the Boeing/AFOSR Mach-6 quiet tunnel at Purdue University) is used to compute, and it is agrees with our computational results.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.1
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• pp.151-157
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• 2010

This paper proposes the Pyramid strategy which is based on the straddle sell. The Pyamid strategy has multi-entry features with starting date and delta parameters. And It is hedged against a loss by mutual trades and dynamic ripples. This paper analyzes the profit and MDD(maximum draw down) of the Pyramid strategy on system trading. The portfolio tool is used for the experiment which is one of the Multicharts' package. The Multicharts is a good trading system of recent years. For the experiment, three call options and three put options are used at october in 2009. Two parameters are used which are the starting date from first October to twentieth October in 2009 and delta from eight percent to fifty percent. As a result, the profit of composite option is about 3 million won. If the strategy starts before the beginning of option month, investors feel uncomfortable because of a large MDD. If a delta belows 20%, it shows high profit and the ratio of profit and MDD builds up a low value. However a low delta makes frequent trades and results in a loss unless increasing entry levels which mean more amount of investment. This work provides a safer trade system than native option trades. It is important how much levels of multi-entry are acceptable. And an amount of investment with appropriate levels of multi-entry is a subject of a future study.

• Journal of Internet Computing and Services
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• v.9 no.3
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• pp.79-90
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• 2008

This paper introduces how we have designed and implemented an efficient starting line-up system of professional baseball players, using the forward chaining technology which is an expert system technology. The knowledge base adopted holds 286 players and 148 evaluation Items. Each player's competitiveness is measured as a numerical value in points through 2 different phases. The 1st phase point represents the static information of the target player and the 2nd his dynamic information. This paper gets a representative value of the player, which is used as the basis on which an efficient line-up system in views of both game environments and counterparts is constructed.

• Journal of the Korea Society of Computer and Information
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• v.21 no.3
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• pp.91-96
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• 2016

We have surrounded undesired living noises in our life. One of biggest noises coming out of range hood during cooking in the kitchen. A range hood is one of the most important appliances in the kitchen because it ventilates polluted air out during cooking, and maintains air quality in the kitchen. But current kitchen range hoods bring up some issues; First, the range hoods consume massive amount of standby power not in use condition. Second, current models have designed manual fan operating system with sudden onset of noise with starting. In this paper, we propose an auto control system entire processes from air ventilation to noise reduction. Our system is consist of three parts (Eco-sensors pack, Main Controller and Active Noise Controller); Eco-sensors pack detects air pollution of kitchen areas and sends the detection values to Main Controller. Main Controller determines operation of range hood by detected values. Active Noise Controller is located inside of the range hood. It received starting signals from Main Controller which elicits degrees of polluted air condition and fan operating speed from 1 to 3. Once Active Noise Controller detected the signals, it runs a ventilating fan until new value from Main Controller becomes 0. while the range hood works, A noise cancellation algorithm inside of Active Noise Controller become activated to reduce levels of noise. As a result, the proposed system clearly shows reduction in power consumption include standby power and decreases in levels of noise.

• Health Policy and Management
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• v.28 no.3
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• pp.197-201
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• 2018

There is a general consensus that many health care problems are attributable to the structural defects of the health care delivery system in Korea. The basic policy aimed to address these problems is to reform the delivery system so as that it incorporates two core principles: (1) stratification of medical care institutions into primary, secondary, and tertiary care providers according to the capability to perform specialized and complex services; (2) patients seeking care starting from the primary care provider and, if necessary, to be referred to the other provider step by step. This policy has been consistently pursued for about 30 years, but the achievement is far from success. Thus it is believed that the feasibility of the policy should be questioned. Starting from this question, based upon the observation of the current structure of the delivery system and its expected changes, the reform policy was discussed focusing on the assessment of its feasibility from both practical and theoretical viewpoints. The discussion leads to cast doubt on the policy for its possibility of making planned changes and producing expected desirable effects. Therefore it is advisable to investigate a wide range of alternative strategies and models for improving health care delivery.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.6
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• pp.35-42
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• 2019

In this paper, we analyze the practical problems of the regenerative start method proposed to improve the starting characteristics of the TBM(Tunnel boring machine)system and propose a solution. In order to solve the speed ripple problem in the previous research results, we first analyze the problems occurring in the system and propose a method to compensate for them. By applying the improved method to the actual system, we compared the results with the conventional system and verified the effect of the proposed method.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.6
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• pp.46-56
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• 1998

This study was performed to investigate thermal performances of two different types of flat-plate solar collector systems; natural circulation system and forced circulation system. Conclusions obtained from this study are summarized as follows; 1) In the natural circulation system, the total heat amounts retrieved by starting recovery soon after sunrise were ranged from 10.28 to 17.20MJ/m$^2$, while the total heat amounts retrieved by starting recovery after sunset were ranged from 5.31 to 10.77MJ/m$^2$. 2) The collector efficiency in natural circulation system were ranged from 51.1% to 54.1% when the collected heat was retrieved after sunrise and were 65.8~78.0% when the collected heat was retrieved soon after sunset. 3) According to the regression analysis between fluid flow rates and fluid temperature difference at inlet and outlet of collector pipe, there was high regressive corelations with regression coefficient, r, of 0.982. 4) The collector efficiencies estimated for forced circulation system were 73.1~88.6%, and 78.4~94.8%, and 64.2%~74.5%, respectively when fluid circulation rates were 4.2 l/min, and 7.0 l/min, respectively.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2391-2398
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• 2002

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.988-995
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• 2009

One of the most popular services of Telematics is a shortest path finding from a starting point to a destination. In this paper, a dynamic shortest path finding system with forecasting result of traffic flow in the future was developed and various experiments to verify the performance of our system using real-time traffic information has been conducted. Traffic forecasting has been done by a prediction system using Bayesian network. It searched a dynamic shortest path, a static shortest path and an accumulated shortest path for the same starting point and destination and calculated their travel time to compare with one of its real shortest path. From the experiment, over 75%, the travel time of dynamic shortest paths is the closest to one of their real shortest paths than one of static shortest paths and accumulated shortest paths. Therefore, it is proved that finding a dynamic shortest path by applying traffic flows in the future for intermediated intersections can give more accurate traffic information and improve the quality of services of Telematics than finding a static shortest path applying by traffic flows of the starting time for intermediated intersections.