• Journal of the Korean Society for Railway
• /
• v.9 no.2 s.33
• /
• pp.244-249
• /
• 2006

Recently, the SCP(Steel Confined Prestressed concrete) composite girders are developed to improve the characteristic such as displacement, vibration, and heavy dead load due to influence of self weight, and inefficiency of steel section of exiting girder-type railroad bridges. It is needed to verify the economical effciency of newly developed SCP composite girder bridge compared with the conventional girder-type bridges. In this paper, LCC analysis for alternative railroad bridges Is performed and its technique based on level of risk(probability of failure) is suggested. From the results, it may be stated that SCP composite girder bridge is more economical than a conventional one.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.476-485
• /
• 2006

The connection system of steel pile and RC footing is an important structure, because the total load of upper construction should be transferred through this joint construction of different two materials-steel and RC-with strongly changed section area. Although many connection systems have been developed, their structural and economical efficiency and workability are often insufficient. Therefore, a new connecting system was developed to improve the problems of current systems. The divided arc plate could improve the workability and economical efficiency, structural efficiency could be reached by welding construction. The main purpose of the research is to evaluate the structural behavior of the new designed connection system through experiments and numerical analysis.

• Journal of the Korean Society for Railway
• /
• v.9 no.5 s.36
• /
• pp.582-587
• /
• 2006

Since Kyung-Bu High Speed Line has been introduced, a railway electrification has been proceeded rapidly. Therefore, in this study, a specification and application standard for an overhead catenary supporting thin walled steel pole using STKT590 material are proposed in order to improve an economical efficiency. To decide the specification, strength analysis, deflection analysis, deflection test and fracture test are performed. If the supporting structures using high strength materials such as STKT590 are installed, the advantages of cost by the materials price reduction and demand and supply are expected.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.03a
• /
• pp.1009-1019
• /
• 2009

Soil nailing method is widely used in reinforcing slopes and excavating earth. The analysis of nail-reinforced slopes, in order to determine the economical length ratio and nail angle, complicated analytical need to be applied by means of computer programs. Therefor this suggested Soil stability Chart for nailed slopes which may be very useful for pre-design, rapidly design, and final check. Three slope types, three nail length and three nail angles are selected for the stability analysis by using limit equilibrium method of Bishop and French Method. From the above results, this study propose the slope reinforced design charts for dry season and rainy season. This proposed reinforced design charts can check dry season as well as rainy season, also these charts can provide reinforcing requirement, soil nail's economical length ratio and nail angle as well.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.695-700
• /
• 2006

For the precise superheat temperature control of an air conditioner, an electronic expansion valve may be used instead of a thermal expansion valve. In this paper, technical and economical aspects of expansion valves were studied in order to find out the possibility to use an electronic expansion valve to replace a thermal expansion valve.

• Journal of Korean Academy of Nursing
• /
• v.34 no.3
• /
• pp.449-457
• /
• 2004

Purpose: The aim of this study was to analyze economical efficiency of home care service by comparing a cost-utility ratio(CUR) between home care and hospitalization. Method: The analytic framework of this study was constructed in 5 stages: Identifying the analytic perspectives, measurement of costs, measurement of utility, analysis of CUR, and sensitivity test. Data was collected by reviewing medical records, home care service records, medical fee claims, and other related research. Result: The mean of the annual total cost was 23,317,636 Won in home care and 73,739,352 Won in hospital care. QALY was 0.389 in home care and 0.474 in hospital care, so CUR was 299,712,545 QALY in home care and 777,841,266 QALY in hospital care. Conclusion: The findings affirmed that home care had an economical efficiency in the aspect of utility compared to hospitalization. Therefore, the findings of this study can be used to develop a governmental health policy or to expand the home care system. In addition, the cost-utility analysis framework and process of this study will be an example model for cost-utility analysis in nursing research. Therefore, it will be used as a guideline for future research related to cost-utility analysis in nursing.

• Journal of the Korean Wood Science and Technology
• /
• v.28 no.4
• /
• pp.72-82
• /
• 2000

Attempts were made to analyze the behavior of single and multiple-bolted connections through theoretical methods such as European yield theory, empirical approaching method, and semi-rigid theory instead of many experimental methods that have been actually inefficient and non-economical. In the case of a single-bolted connection, if accurate characteristic values of a material could be guaranteed, it would be more convenient and economical to perform the behavior analysis using a model based on the semi-rigid theory, instead of the existing complex yield model, or the empirical formula which produces errors, giving different results from the actual ones. If the variables of equation determining the load and deformation could be appropriately controlled, the analytical method in conjunction with a semi-rigid theory could be effectively applied to obtain the desirably predicted value, considering that the appropriate solution could be derived through a simpler equation using a less difficult method compared to the existing yield model. It is concluded that analytical method with semi-rigid theory can be used in the behavior analysis of bolted connection because our developed method showed excellent analysis ability of behavior until number of bolt is two. Although our analytical method has the disadvantage that the number of bolt is limited to two, it is concluded that it has the advantage than numerical method which complicated and time-consuming.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.7 no.3
• /
• pp.29-40
• /
• 2001

The introduction of coastal vessel traffic services enables vessels in coastal waters to navigate in safety or to get her position with ease and prevents the vessel from becoming cause of casualties. But it needs relatively huge amount of cost to construct and operate and maintain. Thus we must be checked with economical adequacy of the the proposed coastal vessel traffic services by comparing the cost of the construction, operation and maintenance with the expected benefit made by the expected decrease in marine casualties. In previous paper, a proper cost-benefit analysis model for the Korean practice will be suggested. In this Paper, the proposed the cost-benefit analysis model of coastal vessel traffic services was applied to the Koje coastal waters 20mi1es from the top of Maemul-Do and Yokchi-Do. As the result, we confirmed the propriety of the cost-benefit analysis with the application of the proposed model to Koje waters. Also, it is verified that the introduction of coastal vessel traffic services, as proposed, is adequate and economical. The cost-benefit analysis model proposed in this study could be used to investigate the economic Propriety of new aids to navigation and traffic safety facilities in the future.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.5
• /
• pp.1-8
• /
• 2019

Breath analysis using a portable device is better than the classical breath analysis system in terms of installation and operation. There is an increasing need to develop cost-effective equipment for testing gas sensors from the viewpoint of functionalities that can be applied applicable to portable devices. In the present study, an economical gas chamber for in-situ gas measurement is implemented with a single gas chamber without using expensive gas storage and control equipment; the gas response characteristics are analyzed using the above-described chamber. The main features of the implemented gas chamber are simple injection procedure, improved gas diffusion, easy measurement and cleaning, support for low-power mode measurement function for portable devices, and open source platform. Moreover, an analysis of gas response characteristics based on changes in sensor voltage show that the sensitivity and 90% response time are affected by the sensor voltage. Furthermore, the sensitivity graph has an inflection point in a specific range. The gas sensor applied in this study showed fast response speed and high sensitivity for sensor voltages of 3.0-3.5 V, regardless of the concentration of acetone gas, the target gas used in this study.

• Proceedings of the Korea Technology Innovation Society Conference
• /
• 2002.11a
• /
• pp.279-292
• /
• 2002