• Journal of the Korean institute of surface engineering
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• v.45 no.2
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• pp.89-94
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• 2012

A study to replace a high temperature thermal carbonization process with microwave plasma process is carried for PAN fiber as a starting material. Near atmospheric pressure microwave plasma (1 Torr~45 Torr) was used to control to get the fiber temperature up to $1,000^{\circ}C$. Even argon is an inert gas, its plasma state include high internal energy particles; ion (15.76 eV) and metastable (11.52 eV). They are very effective to lower the necessary thermal temperature for carbonization of PAN fiber and the resultant thermal budget. The carbonization process was confirmed by both EDS (energy dispersive spectroscopy) of plasma treated fibers and OES (optical emission spectroscopy) during processing step as a real time monitoring tool. The same trend of decreasing oxygen content was observed in both diagnostic methods.

• Journal of the Korean Institute of Plant Engineering
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• v.23 no.4
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• pp.85-92
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• 2018

With the increasing use of chemicals in domestic businesses, the possibility of fire explosion and poisonous material leakage accidents is also increasing. Accordingly, the Korea Occupational Safety and Health Agency(KOSHA) has implemented the process safety management (PSM) system for a long time. However, process safety report submission has been providing and operating e-PSM since 2016 to address these problems as it is difficult to increase budget spending due to the need for professional capabilities and commissioning the report to consulting institutions. Therefore, this study conducts questionnaires on whether e-PSM system that is well utilized in the field, focusing on existing PSM business sites. In order to find out the activation method that can solve the deficiency factors by analyzing various inconveniences and problems accurately, we propose three improvement methods as educational aspect, promotional direction of e-PSM system, and institutional aspect.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.195-200
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• 2021

In recent years, Vietnam's economic growth rate has been attributed to the growth of many well-managed industries within Southeast Asia. Among them is the civil construction industry. Construction projects typically take a long time to complete and require a huge budget. Many socio-economic variables and factors affect total construction project costs due to market fluctuations. In recent years, crucial socioeconomic development indicators of construction reached a fairly high growth rate. Also, most infrastructure and construction projects have a high degree of complexity and uncertainty. This makes it challenging to predict the accurate project price. These challenges raise the need to recognize significant factors that influence the construction price index of civil buildings in Vietnam, both micro and macro. Therefore, this paper presents critical factors that affect the construction price index using the fuzzy extent analysis process in an uncertain environment. This proposed quantitative model is expected to reflect the uncertainty in the process of evaluating and ranking the influencing factors of the construction price index in Vietnam. The research results would also allow project stakeholders to be more informed of the factors affecting the construction price index in the context of Vietnam's civil construction industry. They also enable construction contractors to estimate project costs and bid rates better, enhancing their project and risk management performance.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.202-203
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• 2020

Unlike price calculation by cost accounting, which categorizes costs into material costs, labor costs, and miscellaneous expenses to determine the construction budget price, construction cost calculation based on Construction Standard Unit Prices utilizes unit prices extracted from market prices of items from projects already completed to estimate costs of similar construction projects. Although unit price information is collected through construction site surveys to revise these construction standard unit prices every year, but due to the limitations of the site survey method, it is difficult to quickly implement the rapid changes in the construction methods and market prices. As such, an important issue that arose was the identification of work items whose prices need urgent revision. This study conducted research on factors that need to be considered when developing online survey system for monitoring construction site market prices. This study is expected to enhance convenience for users, and provide an efficient data collection and management system for administrators.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.639-640
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• 2015

Traditional construction planning based on historical data and heuristic adjustment can no longer incorporate all the operational details and guarantee the expected performance. The variation between the expected and the actual production leads to cost overruns or delay. Although predicting reliable productivity on construction site is getting more important, the difficulty of this increases. In this regard, this paper suggested to develop BIM-integrated simulation framework. This framework could predict productivity dynamics by considering factors affecting on construction productivity at operational phase. We developed the following processes; 1) enabling a BIM model to produce input data for simulation; 2) developing the construction operation simulation; 3) running simulation using BIM data and obtaining productivity results. The BIM-integrated simulation framework was tested with structural steel erection model because steel erection work is one of the most critical process influencing on the whole construction budget and duration. We could improve to predict more dynamic productivity from this framework, and this reliable productivity helps construction managers to optimize resource allocation, increase schedule reliability, save storage cost, and reduce material loss.

• Korean Institute of Interior Design Journal
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• v.21 no.1
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• pp.220-227
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• 2012

After The Ramsar Convention took place in Korea in 2008, public interest in environment heightened, and the government has been allocating its budget for conserving our environment. Therefore, the present study focuses on eco-friendly spatial images particularly shown in ecological museums in Korea which recognizes the value of the environment and the ecology and tries to both protect them and alert people about it. The purpose of this study is proving what consist of eco-friendly spatial images by analyzing the expressive word of eco-friendly images and the image of space, providing a basic data for future space planning of ecological museums. To do this, the present study proceeds in three steps. First of all, the base of research in analyzing stage is firmly established by grasping general theories and terms regarding spatial image. As a second step, the composition and the characteristics of exhibition is clarified through on-spot investigation to provide comparative data for spatial image assessment in the future. Also through this step, we could understand how the exhibits are designed currently. In the last stage of research, expressive words regarding eco-friendly spatial images are extracted and used to analyze the spatial image of ecological museums. And the following three conclusions is deduced. First, the expressive words of eco-friendly spatial image that are extracted are as following: "healthy", "coexisting", "clean", "blending", "warm", "soft", "lively", "pure", "cool", "fresh ", "comfortable", "relaxed", "mild", "free", "harmonious", and "healing". As the second conclusion, color, and material, the formation which is an architectural factor did not have a great impact on forming eco-friendly image, but the color and the material did. The third conclusion was that the display with natural aspects actively utilized increased eco-friendly spatial image.

• Journal of Korean Society for Quality Management
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• v.40 no.3
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• pp.245-258
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• 2012

Purpose: Recently, many quality issues are aroused in military forces, such as failures in K-series weapons, combat boots defects and 40mm ammunition explosion accident. To address these problems, the one and only government defense quality assurance agency, DTaQ(Defense Agency for Technology & Quality) tried to improve many quality assurance procedures and introduced new systems such as MRA(Manufacturing Readiness Assessment), TRA(Technology Readiness Assessment), and etc. However, as the amount of war supplies increasing every year, the resource(budget and manpower) for quality assurance is limited. Therefore, DTaQ had difficulty to handle the issue efficiently and effectively, and we propose the method to address this problem. Methods: The most popular quality assurance technique is a sampling method, in this research, we first review the many sampling techniques and compare the strength and weakness of each method. After then, we selected the most appropriate sampling techniques and applied the procedures in combat force support material and ammunition areas. Results: We can reduce the number of samples dramatically, thus the required amount of labor time and money can be saved. Also, the new sampling technique enforces the supplier to produce the product which meets the target value(desirable value). Conclusion: We can reduce the number of samples dramatically, thus the required amount of labor time and money can be saved. Also, the new sampling technique enforces the supplier to produce the product which meets the target value(desirable value). Lastly, since the new sampling method requires many numerical calculations, we developed a simple android OS smart-phone application which can be used easily in field.

• Journal of Korean Society on Water Environment
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• v.34 no.5
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• pp.470-486
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• 2018

This study is to investigate the allochthonous load and water quality of a typical river-reservoir, Paldang during spring (March ~ May) of 17 years (2001 ~ 2017). Phosphorus loading from point sources seems to have been reduced by 74 % in the 2010s. As a result, trophic state of the Paldang reservoir, eutrophic during the 2000s, has returned to the lmesotrophic state. Along with decrease in phosphorus concentration, standing crops of algae (Chl.a) decreased, and concentration of biodegradable organic material decreased to the past level. Concentration of total suspended solids has decreased, and it is due to the decrease of phytoplankton standing crops since the mid-2000s. As transparency increased, it is estimated that euphotic area increased by 22 % and euphotic capacity expanded by 27 %. In the river/transition zone of Paldang, concentration of organic matter increases slightly due to algal growth, but concentration of all water quality items decreases in the lacustrine zone. Although algal growth rate revealed positive correlation with concentration of phosphorus, it was insignificant. Algal growth appeared to be dependent on renewal of phosphorus by flow, than either flow rate or phosphorus concentration. The empirical model including inflow phytoplankton concentration fit well with observed values, and indicates the Paldang reservoir is greatly influenced by allochthonous loads.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.276-279
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• 2004

Plasma enhanced chemical vapor deposition (PECVD) of silicon nitride (SiN) is a proven technique for obtaining layers that meet the needs of surface passivation and anti-reflection coating. In addition, the deposition process appears to provoke bulk passivation as well due to diffusion of atomic hydrogen. This bulk passivation is an important advantage of PECVD deposition when compared to the conventional CVD techniques. A further advantage of PECVD is that the process takes place at a relatively low temperature of 300t, keeping the total thermal budget of the cell processing to a minimum. In this work SiN deposition was performed using a horizontal PECVD reactor system consisting of a long horizontal quartz tube that was radiantly heated. Special and long rectangular graphite plates served as both the electrodes to establish the plasma and holders of the wafers. The electrode configuration was designed to provide a uniform plasma environment for each wafer and to ensure the film uniformity. These horizontally oriented graphite electrodes were stacked parallel to one another, side by side, with alternating plates serving as power and ground electrodes for the RF power supply. The plasma was formed in the space between each pair of plates. Also this paper deals with the fabrication of multicrystalline silicon solar cells with PECVD SiN layers combined with high-throughput screen printing and RTP firing. Using this sequence we were able to obtain solar cells with an efficiency of 14% for polished multi crystalline Si wafers of size 125 m square.

• Fashion & Textile Research Journal
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• v.21 no.5
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• pp.665-676
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• 2019

This study provides basic data for future design proposals aimed at improving the uniforms and bullet/stab proof garments of local police. An analysis was conducted on various aspects of the uniforms used until 2015 and those newly introduced in 2016. Current bullet/stab proof garments were compared with old stab proof garments; in addition, police force posting on the internal SNS were analyzed in regards to the improvement needs for uniforms. Analyses results are as follows. As for the uniforms, convenience was improved by eliminating the necktie, and the four trigrams embroidery was added to emphasize the Korean identity. Cargo-style pants were added for enhanced activity, and the color of the top was changed to turquoise to improve discrimination. In terms of material, durable polyester was used heavily in outside uniforms that were likely to be damaged during work; consequently, the percentage of elastic materials was increased for improved activity. The price showed a high increase rate due to inflation and the use of functional new materials. Complaints and demands for improvement continued despite various modifications made to uniforms and suggested a strong need for further improvements that reflected the opinions of wearers. As for the protective garments, there was a limit to reducing the final weight despite the use of lightweight material because of protection performance enhancements made from expanding the protection surface area. Also, considering further decrease in supply rate, it was deemed necessary to secure budget for full supply of bullet/stab proof garments.