• Convergence Security Journal
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• v.8 no.4
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• pp.121-126
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• 2008

It is of great practical interest to decide when to stop testing a software system in development phase and transfer it to the user. This decision problem called an optimal release policies. In this paper discussed to specify an optimal release policies. In this paper, propose an optimal release policies of the life distribution applied Erlang distribution of special pattern of Gamma distribution. In this paper, discuss optimal software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement. From Sensitivity Analysis, make out estimating software optimal release time.

• Journal of the Korea Safety Management & Science
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• v.12 no.2
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• pp.75-82
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• 2010

Gas turbines for power generating operate in a very high temperature condition and use natural gas for fuel. For this reason, many cases of damage happen at hot gas parts which are severely affected by high temperature gas and many cases of explosion occur by fuel gas. So a lot of efforts should be made to prevent hot gas parts damage and gas explosion accidents. Though there are many damage cases and explosion accidents, it is very difficult to find out the root causes of hot gas parts damage caused by gas explosion due to gas leakage in the heat exchanger for air cooling and gas heating. To prevent gas turbine from damage caused by gas explosion, removal of leakage gas from gas turbine is inevitably required before firing the gas turbine and installing alarm systems is also required for detecting gas leakage at stop valve to turbine while shut down.

• Journal of Sensor Science and Technology
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• v.19 no.3
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• pp.221-229
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• 2010

In recent studies, many methods have been studied for mobile robot using magnetic markers on its pathway. This is not influenced by the weather conditions, and makes possible to develop controller with low level processors and simple algorithms. However, the interval between magnets is restricted by the magnetic field intensity and it is impossible to get road information ahead. This paper suggests a method of widening markers and expressing the road information ahead using magnetic markers, and explains a sensor arrangement considering suggested methods. Also, magnetic field analysis was done to investigate the effects of widening magnetic markers with various environments. A small mobile robot was made to figure out the performance of suggested methods, and driving experiments were performed on the straight and curved road with magnetic markers. The results show that the robot moved the prearranged pathway with 0.5 cm lateral displacements and stopped at a stop line using magnetic information on the road.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.258-259
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• 2007

In this paper, the secant method is adopted to improve a transfer function required by specific filtration properties. It is advantageous over the conventional and widely used 'Template method' in that it enables users to seek the position of a pole which will turn out to meet well the requirements of in-band insertion loss as well as stop-band rejection even after a small number of iterative steps. For validating the proposed method, the transfer function of a 4-pole waveguide filter is targeted.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.1044-1049
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• 2001

Classical deconvolution methods for source identification following linear filtering can only be used if the transfer function of the system is known. For many practical situations, however, this information is not accessible and/or is time varying. The problem addressed here is that of reconstruction of the original input from only the measured signal. This is known as 'blind deconvolution'. By using Higher Order Statistics (HOS), the restoration of the input signal is established through the maximisation of higher order moments (cumulants) with respect to the characteristics of the signals concerned. This restoration is achieved by constructing an inverse filter considering the choice of the initial inverse filter type. As a practical application, an experimental verification is carried out for the restoration of our impacting signal arising in the response of a cantilever beam with an end stop when randomly excited.

• International Journal of Railway
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• v.2 no.1
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• pp.22-29
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• 2009

A simple pendulum shows how efficient gravity is in recovering energy. Any transportation is a linearly oscillating system; every load gains kinetic energy, but loses the same to come to a stop. The Gravity Power Towers comprise of a set of vertically moving heavy masses coupled, through microprocessor controlled continuously variable gear and cable system, to a horizontally rolling unit on wheels either on rail or road. The heavy masses move vertically up against gravity gaining potential energy while stopping a moving mass; move down under gravity force, giving out energy. The Tower thus accelerates or sustains the speed a rolling unit, and while decelerating, recover the kinetic energy. Speeds of 360 kmph can be attained. Recovery of energy varies from 98.5-70%; the longer the distance between stops, the lesser is recovery. The economical, omnipresent & eternal Gravity Power grants energy independence to many a nation. Global warming reduces.

• Journal of Korean Dental Science
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• v.14 no.1
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• pp.32-39
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• 2021

'Crossed occlusion' is the condition in which occlusal intercuspation is lost when several teeth on upper and lower jaw remain. This report describes a clinical case in which a patient had two upper-left posterior teeth and two lower-right posterior teeth; typically known as left-right crossed occlusion. Considering the patient's general condition and financial situation, the treatment plan included placement of two implants on each jaw against the remaining teeth using surgical guide. To find out the ideal position of implants, digital diagnostic wax-up was preceded by superimposing the cast and cone beam computed tomography image, which was aided with radiographic stents. The consequent surveyed implant bridge provided stable vertical stop for fabrication of the implant assisted removable partial dentures. The patient was satisfied with the functionality and esthetics of definitive prosthesis.

• International Journal of Knowledge Content Development & Technology
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• v.11 no.1
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• pp.7-27
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• 2021

High unemployment rates repeatedly cause recurring social problems such as fewer employment opportunities and employment insecurity. Following this trend, various programs related to employment have been provided through various government and institutions. However, they have established overlapping policies and programs and there is no one stop gateway to find effective and efficient way to find relevant information. For this purpose, this study aims to provide employment and job search subject gateway development. The study has carried out case studies, literature reviews, and user survey. Based on this study, it suggested a linked metadata model to organize and link scattered information together, and a digital gateway operating diverse information services. It is expected to provide a basis to develop comprehensive information service model for employment.

• Journal of Environmental Health Sciences
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• v.43 no.1
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• pp.64-70
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• 2017

Objectives: The purpose of this study is to examine the effect of the raise of cigarette prices by KRW 2,000 at the beginning of 2015 on the change in smoking behavior among male office workers, and to analyze the correlation of various factors including their work behaviors and socio-economic factors with their smoking rate. Methods: In this research, a follow-up observation panel was constituted with 420 smokers as targets from among male office workers at a bank located in Daegu, South Korea. A cross-analysis and ANOVA analysis were carried out in order to examine whether changes in smoking status, amount of smoking, stop-smoking motivation, and reasons for smoking cessation failure after the passage of time since the cigarette price hike were statistically significant. The level of statistical significance was P < 0.05. Results: After the cigarette price hike, among the 420 smokers who were the target of the panel the rate of smoking cessation declined at the time-point of the survey to 15.5%, 12.4%, 8.5%, and 5.7% after one month, three months, six months, and 12 months, respectively. As a result of a follow-up observation of 65 smokers who stopped smoking immediately after the price hike, the actual non-smoking rate declined to 15.5%, 8.3%, 4.4%, and 3.1% after one month, three months, six months, and 12 months, respectively. One (1) year after the cigarette price hike, the non-smoking rate among the 420 smokers reached as low as 3.1% (13 persons). The most important reason for the failure of the attempts to quit smoking was stress for more than 60% of the smokers who attempted to stop. Conclusions: It seems that a powerful anti-smoking policy by the state targeting the nation's workers is necessary. For companies, mediation for workers' job stress can become a strategy for the success of non-smoking attempts. The government seems to require a practical policy to reduce the smoking rate by actively carrying out social, economic, and scientific research to come up with a reduction method for the cigarette hazard, an effective price hike policy, and other non-price policies.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.3
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• pp.112-123
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• 2012

Different from general roads, intersections are the points where roads having different geometric structure and traffic operation system are met, and thereby they have complicated road structure and environmental factors. Various changes in driving patterns such as collision between vehicles approaching from roads adjacent to intersections, sudden stop of vehicles upon stop sign, quick start upon green lights kept increasing traffic accidents. It is known that traffic accidents are mainly derived from human factors. This study, in order to find out factors affecting drivers' behaviors within intersections, measured physiological responses such as brain wave, sight, driving speed, and so on by using state-of-the-art measuring device. As to concentration brain wave at individual intersections, it was found out that brain wave of testes was higher at main Arterial and accident-prone intersections compared with that of subsidiary Arterial. In addition, it was detected that drivers' visual activity was widely distributed at accident-prone intersections, meaning that it enhanced cautious driving from nearby vehicles. As to major factors causing drivers' workloads, factors from nearby vehicles such as deceleration, acceleration, lane change of nearby vehicles appeared as direct factors causing drivers' workloads, clarifying that these factors were closely related to causes of traffic accidents at intersections. Results of this study are expected to be used as basic data for evaluation of safety at intersections in consideration of physiological response of drivers.