• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.179-184
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• 2012

Environmental impact is getting more attention in many feasibility studies for railroad-related projects and research items. For sustainable growth and green transportation, the benefits typically used for feasibility studies in railway-related projects, are composed mostly of economic criterions which is not considering growing attention on changing paradigm. Based on the analysis of current methodologies, improvements in estimating environmental impact especially on noise and pollution are suggested. Active steering bogie has been proposed to satisfy stabilizing and steering performance of railroad. This paper describes the feasibility study of the active steering bogie for a urban railway vehicle based on environment-related criteria.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.2
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• pp.52-57
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• 2011

The procedures of Continuous Descent Approach(CDA) is designed to minimize the thrust required during landing, thereby reducing fuel consumption, noise and emissions compared to conventional approach procedures. Widespread implementation of CDA would result in significant reductions in the environmental impact and aircraft operation costs. This paper estimated the possible economic effects from the perspective of airliners through cost-benefit analysis, provided that the CDA is introduced. It is now proposed that a more comprehensive analysis model, which includes the reduced ATC communication burden between controllers and pilots, not to mention the economic aspect, should be established for the improvement.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1178-1183
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• 2006

This paper describes the plans of considering the environmental influences in the preliminary feasibility investigation of railroad work. Because the cost-benefit analysis method about the environmental costs by air pollution and traffic noise is mainly applied in preliminary feasibility investigation, not only the verification in the calculation method of these environmental costs but also the consideration in the environmental costs of the topographical damage and the ecosystem extinction by railroad work is needed. The environment-friendly plans in choosing the locations of the railroad route and station are also suggested, and they include (1) consideration of environment protection area, residential zone, and region with scenic beauty, (2) application of the existing railroad route and station, and (3) railroad route parallel to another traffic facility.

• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2339-2345
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• 2020

Radiation imaging systems consisting of a large number of channels greatly benefit from multiplexing methods to reduce the number of channels with minimizing the system complexity and development cost. In conventional pixelated radiation detector modules, such as anger logic, is used to reduce a large number of channels that transmit signals to a data acquisition system. However, these methods have limitations of electrical noise and distortion at the detector edge. To solve these problems, a multiplexing concept using a digital signal encoding technique based on a time delay method for signals from detectors was developed in this study. The digital encoding multiplexing (DEM) method was developed based on the time-over-threshold (ToT) method to provide more information including the activation time, position, and energy in one-bit line. This is the major advantage of the DEM method as compared with the traditional ToT method providing only energy information. The energy was measured and calibrated by the ToT method. The energy resolution and coincidence time resolution were observed as 16% and 2.4 ns, respectively, with DEM. The position was successfully distributed on each channel. This study demonstrated the feasibility that DEM was useful to reduce the number of detector channels.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.42-51
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• 2017

Due to the high degree of mechanization and the good environmental benefits, the prefabricated buildings are being promoted in China. The construction site layout of the prefabricated buildings has important influence on its safety benefit. However, few scholars have studied the safety problem on it. Firstly, in order to give a follow-up study foreshadowing the characteristics of prefabricated buildings are analyzed, the research assumptions are given and three types of safety buffers are established. And then a mult-objective model for the prefabricated buildings site layout is presented: taking into account the limits of noise, the coverage of the tower crane and the possibility of exceeding boundaries and overlapping, the constraints are and designed established respectively; Based on the improved System Layout Planning (SLP) method, the efficiency\cost\safety interaction matrices among the facilities are also founded for objective function. For the sake of convenience, a hypothetical facility layout case of the prefabricated building is used, the optimal solution of that is obtained in MATLAB with particle swarm algorithm (PSO), which proves the effectiveness of the model presented in this paper.

• Journal of Korean Society for Quality Management
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• v.43 no.4
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• pp.589-606
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• 2015

Purpose: In developing new products, reducing performance variation is important for competitiveness factors such as quality, cost, and delivery. This paper aims at evaluating three performance variations; measurement, performance evaluation, and manufacturing variations, and then improving product and process design, focused on paper helicopter making case study. Methods: For measurement system analysis, gage R&R (repeatability and reproducibility), linearity, stability are evaluated. Since gage R&R are not satisfactory, the measurement system is improved by adopting voice memos application of iPhone and providing standard measurement procedure. To evaluate performance variation, product deterioration and environment factor (wind speed) is considered. Since the existing design is sensitive to these noise factors, a new product design is developed, which is proven to be robust to the noise factors. Finally, manufacturing variations are evaluated with five factors which can cause variation in flight time. To reduce the impact of three significant factors, three improvement methods are applied. Results: Three performance variations are evaluated and robust paper helicopter design is presented. Conclusion: To reduce measurement and process variations, improved measurement method and paper helicopter making procedure are proposed. A new product design is also presented which is robust to deterioration and environmental variation. This paper is expected to benefit students and practitioners who want to have hands-on knowledge on new product quality improvement.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.279-282
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• 2015

Fisheries development of the basic law pursuant to article 15 (marine safety management, etc.) one of maritime safety and maritime traffic facilities nationwide network of DGPS in accordance with the building maximize infrastructure utilization and country. Source technology has been improving steadily raised for the benefit daegukmin. In particular, look at the type of product for the marine supply medium-wave receiver Performance products that satisfy most of the IMO Advisory. The antenna and receiver are separate structural supply for some integrated model with a very high Rather it is used as a portable receivers for marine positioning cheap integrated model development is needed. Correction of satellite navigation receivers for the current Marine GPS module, medium-wave modules can be developed one low cost Integrated in independent operating environments do not support the model development done look at what the problem is 285kHz ~ 315kHz in DGPS Beacon receiver structure using a medium wave or Beacon The medium-wave antenna and a GPS receiver signal to noise ratio was studied GPS signal attenuation on the DGPS performance looked at each GPS manufacturer medium-wave signal-to-noise ratio and normalized impact by GPS manufacturers noise power ratio per bandwidth for medium-wave GPS signals affect it was implemented to improve performance.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.61-77
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• 2019

If a new utility tunnel is planned for high density existing urban areas in Korea, a rational decision-making process such as the determination of optimum design capacity by using the feasibility evaluation system based on quantitative evaluation indexes and the economic evaluation is needed. Thus, the previous study presented the important weight of individual higher-level indexes (3 items) and sub-indexes (16 items) through a hierarchy analysis (AHP) for quantitative evaluation index items, considering the characteristics of each urban type. In addition, an economic evaluation method was proposed considering 10 benefit items and 8 cost items by adding 3 new items, including the effects of traffic accidents, noise reduction and socio-economic losses, to the existing items for the benefit cost analysis suitable for urban utility tunnels. This study presented a quantitative feasibility evaluation method using the important weight of 16 sub-index items such as the road management sector, public facilities sector and urban environment sector. Afterwards, the results of quantitative feasibility and economic evaluation were compared and analyzed in 123 main road sections of the Seoul. In addition, a comprehensive evaluation method was proposed by the combination of the two evaluation results. The design capacity optimization program, which will be developed by programming the logic of the quantitative feasibility and economic evaluation system presented in this study, will be utilized in the planning and design phases of urban community zones and will ultimately contribute to the vitalization of urban utility tunnels.

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.19-33
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• 2001

In the developed countries, traffic noise is one of most serious problems faced by people's lives. So the importance of the traffic noise is quite well recognized by the infrastructure planners as well as the people. The traffic noise is valued in monetary terms in some countries and it is reflected in estimating the net present value or benefit/cost ratio. On the contrary, the effects of traffic noise are not reflected in the assessment of infrastructure in most cases in Korea. However, as the income level has been increasing, more people have been becoming to put more importance on their living conditions. The purpose of this paper is to estimate the value of traffic noise in the Seoul metropolitan area. The housing price were surveyed to use the quasi-hedonic price technique. By this way, two housing prices at the same floor level in different 128 complexes in the Seoul metropolitan area were surveyed. the actual traffic noise level was also measured. The differences of housing prices and noise levels were analyzed using the various types of regression models. The value is quite different by size of house. The value of large house is higher than that of small house. Since the income level of people in large house is higher than that in small house. it might be said that value of traffic noise for high income people is higher than that for low income people. Moreover, the increase of 1dB(A) noise affects the house price by about 0.3% in Seoul metropolitan area.

• Journal of Environmental Impact Assessment
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• v.21 no.2
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• pp.297-314
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• 2012

This study investigates the stigma effect of unwelcomed facilities on apartment prices through multiple regressions based on hedonic price method. The areas studied are Sang-gye Jugong 7, 9, 10 apartment complexes. The facilities analyzed are the Chang-dong Electric Subway Depot and the Do-bong Driver's License Agency. The factors studied include the environmental variable (the elapsed time since the announcement of the re-location of these facilities), the view commanding, the distance from Chang-dong Depot, the distance from Do-bong Driver's License Test Course, the distance from neighboring facilities (subway stations, schools, parks and so on), the floor and each dwelling's exclusive space. The data used are 2,822 sales which have been collected since January 1, 2006. The facts found are as follows; first, the view commanding and the distance from the unwelcomed facilities are statistically significant. second, the environmental variable, 'days' turns out to have a positive (+) and a negative (-) significant relationship with the dependent variable, 'price', in period II and period IV respectively. This implies that the stigma effect is real. third, there are significant differences in the influence on the apartment prices among the independent variables according to time. fourth, the stigma effect is estimated as 33,686,920 Korean won in the case of the apartments which have the view commanding and 30,311,844 won in the other case before the global economic crisis. This effect seems to decrease to 22,085,078 won after the crisis. These facts suggest that stigma effects could be considered as one of the benefits in the cost-benefit analysis of Chang-dong Depot re-location project to produce somewhat higher NPV or B/C ratio.