• Proceedings of the KSR Conference
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• 2011.10a
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• pp.27-37
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• 2011

Currently, in the course of introducing rolling stocks, RAMS standard and management by system engineering method apply to rolling stock system. Technical elements and results applied in system introduction phase are just used in acquisition stage, and these are not applied to the standard in railway site. Therefore, it is difficult to apply to standardized technology and quality assurance measure. Due to the establishment of the EU, railway operation system is internationalized and the international railway standards are being discussed in various ways. In addition, standardization is expanded from manufacture to operation and maintenance. It is to provide consistent standard in quality, cost calculation of maintenance technology, maintenance technology and quality assurance in case of international railway safety incidents. Therefore, this study is to find technology, quality and cost management model to be used for choosing railway-operation guidance by considering how technologies & quality have changed in system life cycle, compared with estimated standards, based on the technologies & quality-related result in the process of getting new rolling stocks and management guidance for operation & maintenance process.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.912-920
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• 2006

The purpose of this study is to present the design standard for load density in subway station. From the data of electric equipment capacity and electric power consumption for 43 subway stations, current levels of the load density and excess capacity factor were surveyed and analyzed, In addition mean value, standard deviation, maximum value, median value and correlation coefficient were evaluated through excel program. Also it was carried out the regression analysis. The estimation method of load density and design criterion were studied. As a result, load density in this thesis have been proposed : 51.3 $[VA/m^2]$ on the general power load can be a standard value for subway station.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.381-384
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• 2005

The purpose of this study is to develop a prediction model for evaluating heavy-weight floor impact sounds in a test building. Three rooms in the test building (slab thickness In and 240mm), which consist of frame concrete structures were tested and modeled. First, the SPL distribution in the receiving room was analyzed by measuring SPL at 90 positions using a bang machine. Then, a vibration model using finite element method is proposed considering the material properties and boundary conditions. In addition, the result of transient analysis was compared with field measurements using a standard heavy-weight impact source. Through a vibro-acoustic simulation program, an acoustic model evaluating the building elements (reflected wall, nor, window and door) was proposed. Finally, validation of the prediction model was conducted by vibro-acoustic analysis with field measurements of noise radiation characteristics in receiving rooms.

• Journal of Korean Neurosurgical Society
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• v.49 no.4
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• pp.212-216
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• 2011

Objective : It is well known that plate-to-disc distance (POD) is closely related to adjacent-level ossification following anterior cervical plate placement. The study was undertaken to compare the outcomes of two different anterior cervical plating methods for degenerative cervical condition. Specifically, the new method involves making holes for plate screws first with an air drill and then choosing a plate size. The other method was standard, that is, decide on the plate size first, locate the plate on the anterior vertebral body, and then drilling the screw holes. Our hypothesis was that the new technical tip may increase POD as compared with the standard anterior cervical plating procedure. Methods : We retrospectively reviewed 49 patients who had a solid fusion after anterior cervical arthrodesis with a plate for the treatment of cervical disc degeneration. Twenty-three patients underwent the new anterior cervical plating technique (Group A) and 26 patients underwent the standard technique (Group B). POD and ratios between POD to anterior body heights (ABH) were measured using postoperative lateral radiographs. In addition, operating times and clinical results were reviewed in all cases. Results : The mean durations of follow-up were $16.42{\pm}5.99$ (Group A) and $19.83{\pm}6.71$ (Group B) months, range 12 to 35 months. Of these parameters mentioned above, cephalad POD (5.43 versus 3.46 mm, p=0.005) and cephalad POD/ABH (0.36 versus 0.23, p=0.004) were significantly greater in the Group A, whereas operation time for two segment arthrodesis (141.9 versus 170.6 minutes, p=0.047) was significantly lower in the Group A. There were no significant difference between the two groups in caudal POD (5.92 versus 5.06 mm), caudal POO/ABH (0.37 versus 0.32) and clinical results. Conclusion : The new anterior cervical plating method represents an improvement over the standard method in terms of cephalad plate-to-disc distance and operating time.

• Journal of the Korean Wood Science and Technology
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• v.33 no.2 s.130
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• pp.29-39
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• 2005

Formaldehyde emissions from wood-based panels bonded with pine and wattle tannin-based adhesives, urea-formaldehyde resin (UF), melamine-formaldehyde resin (MF), and co-polycondensed resin of urea-melamine-formaldehyde (UMF) were measured by the Japanese standard method using a desiccator (JIS A 1460) and the EN 120 (European Committee For Standardization, 1991) method using the perforator value. In formaldehyde emission, all particleboards made using the wattle tannin-based adhesive with three different hardeners, paraformaldehyde, hexamethylenetetramine, and tris(hydroxyl)nitromethan (TN), satisfied the requirements of grade $E_1$. But only those made using the pine tannin-based adhesive with the hexamine as hardener met the grade $E_1$ requirements. Hexamine was effective in reducing formaldehyde emission in tannin-based adhesives when used as the hardener. While the UF resin showed a desiccator value of $7.1mg/{\ell}$ and a perforator value of 12.1 mg/100 g, the MF resin exhibited a desiccator value of $0.6mg/{\ell}$ and a perforator value of 2.9 mg/100 g. According to the Japanese Industrial Standard and the European Standard, the formaldehyde emission level of the MDF panels made with UF resin in this study came under grade $E_2$. The formaldehyde emission level was dramatically reduced by the addition of MF resin. The desiccator and perforator methods produced proportionally equivalent results. Gas chromatography, a more sensitive and advanced method, was also used. The samples for gas chromatography were gathered during the experiment involving the perforator method. The formaldehyde contents measured by gas chromatography were directly proportional to the perforator values.

• Journal of The Korea Institute of Healthcare Architecture
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• v.25 no.4
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• pp.71-79
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• 2019

Purpose: The manoeuvring space at doors must be secured for users of walking aids, wheelchair users, stroller users, luggage carriers, etc., so clear criteria must be established. The korean standards for the manoeuvring space at doors need to be improved to present clear criteria depending on the type of entrance and the direction of opening and closing. Method: Korean standard, International Standard(ISO 21542, 2011), German Standard(DIN 18040-1, 2010), Austrian Standard(OENORM B 1600, 2017) and Swiss Standard(Norm SIA 500, 2009) were investigated and analyzed. A comprehensive improvement of the criteria for the manoeuvring space at doors is proposed. Results: The manoeuvring space at doors, which is essential for the disabled to use the door, shall be installed with a comprehensive consideration of the width of doors, the Circulation space, the direction of access, and the method of opening and closing of the door. Korean standards, such as the width of doors, the Circulation space, and the manoeuvring space at doors, are different from international and international standards, which require improvement of standards. The criteria for the manoeuvring space at doors shall be clearly improved so as not to be misinterpreted during the installation of doors and the BF-certification. Implication: The criteria for the installation of doors shall be presented as a comprehensive alternative through continued study of details. In addition, improvements in standards that reflect changes in international standards should be made.

• Journal of Ocean Engineering and Technology
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• v.33 no.5
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• pp.479-485
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• 2019

As exhaust gas systems of ships become more complicated, it is necessary to calculate an accurate pressure loss at their design stage. If the dynamic loss coefficients of non-standard fittings mainly used in exhaust gas pipe (EGP) are well-documented, it would be possible to calculate precise pressure loss more readily than using the conventional method that analyzes the entire system. In the case of a ship's EGP, the flow rates and temperatures of exhaust gas are determined by engine specifications, and the range of the flow rate and temperature is limited according to operating conditions. In addition, as it is possible to define non-standard fittings frequently used in an EGP, a database can be easily constructed and effective. This paper illustrates effective parameters and analysis cases of several types of non-standard fittings mounted in ship EGPs. The analysis procedure proposed in this paper is verified using existing research results on HVAC fittings. The numerical procedure, which is minimally affected by manpower and grid, is established such that it can be applied at the industry level.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.67-72
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• 2016

In this study, the texturing and the emitter formation processes were carried out with the wafer adhesion method to increase the productivity and reduce the production cost of the multi-crystalline silicon solar cell. After fabricating $156{\times}156mm$ solar cell according to the wafer adhesion method, the operation characteristics were analyzed and compared with those of the solar cell fabricated by the standard process method. In the case of a solar cell formed by the wafer adhesion method, it showed Jsc of $32.87mA/cm^2$, Voc of 0.612V, FF of 78.04% and efficiency of 15.71% respectively. The efficiency of the solar cell formed by the wafer adhesion method was 0.1% higher than that of the solar cell formed by the standard method. In addition, the productivity of the texturing and the emitter formation processes is expected to be approximately doubled. Therefore, it is expected that the manufacturing cost of the multi-crystalline solar cell can be reduced due to the improved productivity compared with the standard process.

• Journal of the Korean Society of Systems Engineering
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• v.18 no.2
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• pp.1-10
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• 2022

In general, similar or previous projects are mainly referred to in order to derive operational test and evaluation(OT&E) items after acquiring weapon system. The idea that a more systematic method is needed is spreading because some of OT&E items derived in this process are redundant or unnecessary. Therefore, in this topic, we plan to use WBS, a tool that classifies components into a hierarchical structure and manages development easily to achieve the weapon system development goal. In addition, the WBS tool is applied to the medium-sized standard vehicle project, which is currently being research and developed, to effectively derive OT&E items. As a result of deriving OT&E items by applying WBS to the vehicle development field and electric devices of the medium-sized standard vehicle project, the operability and relationship were judged early, and then contents of the evaluation items could be written substantially while working on environmental adaptability. In the future, it is judged that the efficiency will be increased if the method discussed in this paper is applied when deriving the OT&E items from the R&D development project.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.457-468
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• 2011

Recently, the non-vibration mass excavation method is used on sewage pipes and road construction sites in Jeju. However, a construction cost estimation based on the unit quantity does not provide a proper unit price. In this study, a comparison of the productivity of the standard quantity-per-unit costing method and the one of the work crew combination method was made based on the site monitoring of the non-vibration mass excavation method that is used in construction sites near Jeju. For this, data of 35 sites were collected: a regression equation was derived from the 30 data, and verification was carried out through the remaining 5 data. The analysis concluded that a day's workload is $16.43m^3$. In addition, a combination of the equipment considering the site conditions and the amount of labor, which varies with the number of work crew was obtained in order to estimate the construction cost of the work crew combination method. The construction cost was calculated based on the one-day workload ($16.43m^3$) derived from the regression analysis. The cost then was analyzed and compared with the standard quantity-per-unit costing method.