• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.227-230
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• 1998

The interfacial breakdown between two internal dielectric surfaces represents one of the major causes of failure for power cable joint. In order to better understand this phenomenon, breakdown experiments were performed for each interfacial condition at Epoxt/EPDM interface found in cable. The specimen were Epoxy resin and EPDM generally used in cable joint. The interface conditions were three parts. First condition was the pressure of interface, we used the value of 1, 2, 3, 4, 5[kg/cm$^2$]. For the second condition, the sanding condition was treated with sand paper #220, #600, #1200. Finally, we observed the breakdown according to the presence of silicon oil at the interface.

• 소성∙가공
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• 제16권1호
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• pp.54-60
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• 2007

Optimum injection molding condition for a box mold was searched by the Response Surface Analysis(RSA) with the aid of process monitoring system(PMS). Process variables on the control panel of the injection molding machine such as barrel temperatures, screw speed profile, holding pressures, etc. cannot guarantee the uniformity of the material variables directly related with the state of the product in the mold cavity. In order to make sure the state of the resin in the cavity, pressures and temperatures in the cavity, runner and nozzle were monitored in the experiment with the PMS. To accomplish the consistency of the molding process, dependent variables such as the switchover point and holding time were searched with the PMS. With a proper objective function about deflection of the box-type product, the optimum injection molding condition was obtained.

• 여성건강간호학회지
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• 제12권1호
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• pp.5-11
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• 2006

Purpose: The purpose of this study was to analyze the concept, palliation, in order to enhance understanding of palliative care and ultimately lead to the provision of timely quality palliative care. Method: This study used Walker and Avant s methods for concept analysis. Result: The defining attributes of palliation identified in this study were 1) being limited, 2) responsiveness, 3) leading to positive effects, 4) relativity, and 5) being unsettled. The antecedents of palliation were 1) a problematic condition, 2) appropriate management for the problematic condition, and 3) interaction between the problematic condition and the appropriate management. The consequences of palliation included 1) improvement of a problematic condition and 2) dependency on a management of the problematic condition. Conclusion: Although further studies are required to refine the diverse attributes of the concept of palliation, according to this concept analysis of palliation, palliative care should be introduced at the early stage of disease and constantly provided for the improvement of its negative symptoms.

• 여성건강간호학회지
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• 제16권4호
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• pp.381-389
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• 2010

Purpose: The purpose of this study was to analyze the concept seogueulpeum, in order to give a operational definition of middle-aged women's seogueulpeum. Methods: Walker and Avant's methods for concept analysis was used. Results: The defining attributes of seogueulpeum identified in this study were 1) time, 2) negativity, 3) vagueness, 4) passivity, 5) individuality. The antecedents of seogueulpeum were 1) a problematic condition, 2) past event, experiences for the problematic condition, and 3) interaction between the problematic condition and past event, experiences. The consequences of seogueulpeum included 1) to get worse for the problematic condition, 2) passive or active management for the problematic condition. Conclusion: Although further studies are required to refine the diverse attributes of the concept of seogueulpeum, according to this concept analysis of seogueulpeum, this study contribute to explain psychological health of middle-aged women. In addition to develop the adequate interventions decreasing seogueulpeum with aging in women is needed.

• 한국정밀공학회지
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• 제20권4호
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• pp.136-142
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• 2003

The morphological analysis of wear debris can provide early a failure diagnosis in lubricated moving system. It can be effective to analyze operating conditions of oil-lubricated tribological system with shape characteristics of wear debris in a lubricant. But, in order to predict and recognize an operating condition of lubricated machine, it is needed to analyze and to identify shape characteristics of wear debris. Therefore, If the morphological characteristics of wear debris are recognized by computer image analysis using the neural network algorithm, it is possible to recognize operating condition of hydraulic driving members. In this study, wear debris in the lubricating oil are extracted by membrane filter (0.45 ${\mu}{\textrm}{m}$), and the quantitative values of shape parameters of wear debris are calculated by the digital image processing. This shape parameters are studied and identified by the artificial neural network algorithm. The result of study could be applied to prediction and to recognition of the operating condition of hydraulic driving members in lubricated machine systems.

• International Journal of Fluid Machinery and Systems
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• 제5권4호
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• pp.143-151
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• 2012

Predicting the future condition of machine and assessing the remaining useful life are the center of prognostics. This paper contributes a new prognostic method based on grey model and survival probability. The first step of the method is building a normal condition model then determining the error indicator. In the second step, the survival probability value is obtained based on the error indicator. Finally, grey model coupled with one-step-ahead forecasting technique are employed in the last step. This work has developed a modified grey model in order to improve the accuracy of prediction. For evaluating the proposed method, real trending data of low methane compressor acquired from condition monitoring routine were employed.

• 대한설비공학회지:설비저널
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• 제15권4호
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• pp.356-361
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• 1986

An optimum design condition for a basic refrigeration cycle is defined as the condition which minimizes the total cost of heat exchanges (condenser and evaporator) and compressor for the refrigeration effect. Thermodynamic properties of ammonia (R717) are approximated by rational functions in order to obtain the optimum condition for a basic refrigeration cycle. Optimum condition depends on the heat capacity rates (mass flow rate times specific heat) of cooling water and brine used in condenser and evaporator. The difference between the cooling water temperature and condensation temperature at the optimum condition increases as the heat capacity rates and the coat of heat exchangers relative to the cost of compressor increase. Numerical examples of optimum conditions are obtained when the condensation temperature is $30^{\circ}C$ and the evaporator temperature is $-10^{\circ}C$.

• Journal of Advanced Marine Engineering and Technology
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• 제28권6호
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• pp.972-980
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• 2004

Cathodic protection is being widely used to protect steel structures in sea water environment, In order to protect steel structures completely, the flow condition of sea water surrounding with this structures and the surface condition of the structures must be considered for a desirable design of cathodic protection. In this study, the optimum protection potential and current density were investigated in terms of cathodic current density, surface condition and a flow condition of sea water. The optium protection potential of the cleaned specimen was -770 mV(SCE) and below. However in the case of the rusted specimen, its potential was -700 mV(SCE) and below, which was somewhat positive than the cleaned one irrespective of flow condition. The optimum cathodic protection current density for both the cleaned and rusted specimens was 100 mA/$\textrm{m}^2$, however, on the flow condition, 200 mA/$\textrm{m}^2$ to be supplied for cathodic protection of steel structures completely for both cleaned and rusted specimens.

• 한국환경과학회지
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• 제7권5호
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• pp.573-580
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• 1998

This study examined the carbon dioxide ($CO_2$) pollution inside vehicles under low ventilation condition and evaluated the Air Quality System (AQS) for in-vehicle air quality using two techniques. The low ventilation condition is not recommended in order to keep oxygen-rich condition inside vehicles. Under the low ventilation condition, the in-vehicle $CO_2$ concentrations exceeded 1,000 ppm, the air qualify guidelines in the United States, Western Europe, and Japan, indicating more oxygen deficiency inside vehicles. On the contrary, with the AQS-on condition, the in-vehicle $CO_2$ concentrations were less than 1,000 ppm fer most of the driving time, indicating that the AQS could solve the problem of $CO_2$ accumulation inside vehicles under the low ventilation condition. The AQS test conducted by comparing carbon monoxide (CO) and volatile organic compound (VOC) concentrations inside two vehicles indicated that the AQS effectively decreased the in-vehicle concentrations by 21 to 36%, as compared to medium ventilation condition with the windows closed, the vent opened, and air conditioning on. In addition, The AQS test conducted by comparing the interior and exterior concentrations indicated that the AQS effectively decreased the in-vehicle concentrations by 18 to 31%, as compared to medium ventilation condition.

• 한국동물위생학회지
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• 제25권1호
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• pp.15-22
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• 2002

This experiment was carried out to investigate the changes of egg qualify during storage in order to find out the proper storage condition. Fresh eggs were stored at cold condition ($5^{\circ}C$, relative humidity ; RH :$65\pm$3%) and room condition($25^{\circ}C$, RH :$40\pm$3%) during 10 weeks and examined microbiological quality, weight loss and interior quality periodically. Weight loss was indicated 17.93% at room condition and 2.56% at cold condition. The pH of egg white and yolk were increased from 7.94 to 9.03(average 13.72%) and from 6.16 to 6.57(average 6.65%) at cold condition and from 7.94 to 9.54(average 20.15%) and from 6.16 to 6.90(average 12.01%) at room condition respectively. But pH of egg white and yolk did not showed significant difference between before molting and after molting. Haugh unit was decreased from 82.0 to <30 at room condition after 3 weeks. The most frequent bacteria isolated were E coli, Staphylococcus leutus, S saprophyticus, Citrobacter freundii, Klebsiella oxytoca, Providencia rettgeri, and Pontoea spp. It was recommended that shelf life of unrefrigerated eggs would not be longer than 21 days at room temperature in summer.