• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.9
• /
• pp.501-507
• /
• 2018

Owing to the complexity and modernization of weapon systems, the role of the defense industry in producing military supplies has become increasingly important. In previous defense industries, price competitiveness was a key factor in the product choice. On the other hand, as exports of domestic military supplies are expanding rapidly based on superior quality, there is a need to evaluate objectively the efficiency of management in the domestic defense industry. In this study, the efficiency of management was measured using DEA, which is one of the decision methodologies. In addition, the number of employees (QA Employee) and R&D performance were set as input variables to utilize DEA, and the output variables were based on sales and operating profit. Based on the results of the analysis, a future study will measure the efficiency of the management of domestic defense industry to help guide a strategic development plan.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.21 no.4
• /
• pp.104-109
• /
• 2017

It is important to keep the distribution of the raw material mixture constant, in order to maximize the effect of the pre-mix type repair mortar, and it is also necessary to increase the performance of the mixer in order to minimize the deviation of the product. In this study, three kinds of mixer used in production sites were used to make repair mortar and the properties of each mortar were examined. As a result, it is confirmed to the difference in properties of pre-mix type repair mortar differ depending on the type of mixer, and the fluidized zone mixer showed relatively good results. In addition, it is preferable to set the mixing time to about 10 minutes to 15 minutes in order to ensure workability and optimum physical properties.

• Design & Manufacturing
• /
• v.13 no.4
• /
• pp.23-27
• /
• 2019

People's interest in the environmental problems of the Earth is growing as they come to the modern world, and research is being actively conducted on how to protect the environment. As a result, the automobile industry, one of the causes of environmental pollution, is also affected. Therefore, research is being conducted to improve the fuel economy and light weight of cars, development of pollution-free cars such as electric cars, and aluminium materials that are lighter than ordinary steel sheets and easier to recycle are gaining attention. In this experiment, the material was formed to form a form of aluminium and the material reduction rate of the side wall of the foam was tested according to the amount of side wall. The material used in the experiment was A3003-O, which is less plastic than normal steel plates, but has excellent corrosion resistance, plasticity and weldability compared to aluminium materials, but has poor tensile strength. For tensile testing, a certain array of Forming Shapes was molded and the height of the Forming was set to 5mm, and the height of the Forming was 4.7mm, indicating that the difference between the first 5mm Forming and the height was not large. In addition, the material reduction rate was tested by giving 15, 0, and -0.15 teas, respectively, and was found to be valuable as a product only for -0.15.

• International Journal of Aeronautical and Space Sciences
• /
• v.16 no.3
• /
• pp.418-424
• /
• 2015

The chemical response of energetic materials is analyzed in terms of 1) the thermal decomposition under the thermal stimulus and 2) the reactive flow upon the mechanical impact, both of which give rise to an exothermic thermal runaway or an explosion. The present study aims at building a set of chemical kinetics that can precisely model both thermal and impact initiation of a heavily aluminized cyclotrimethylene-trinitramine (RDX) which contains 35% of aluminum. For a thermal decomposition model, the differential scanning calorimetry (DSC) measurement is used together with the Friedman isoconversional method for defining the frequency factor and activation energy in the form of Arrhenius rate law that are extracted from the evolution of product mass fraction. As for modelling the impact response, a series of unconfined rate stick data are used to construct the size effect curve which represents the relationship between detonation velocity and inverse radius of the sample. For validation of the modeled results, a cook-off test and a pressure chamber test are used to compare the predicted chemical response of the aluminized RDX that is either thermally or mechanically loaded.

• Natural Product Sciences
• /
• v.19 no.1
• /
• pp.20-27
• /
• 2013

A simple high performance liquid chromatography - diode array detector (HPLC-DAD) method has been developed and validated for simultaneous determination of the six components (cinnamic acid, cinnamaldehyde, eugenol, atractylenolide I, atractylenolide III, and ergosterol) in Oryeongsan. In addition, identification of six marker compounds was conducted by a LC-MS/MS analysis. The six compounds in Oryeongsan were separated on Shishedo $C_{18}$ column (5 ${\mu}m$, $4.6{\times}250$ mm) at a column temperature of $30^{\circ}C$. The mobile phase was a mixture of 0.1% trifluoroacetic acid (TFA) water and acetonitrile employing gradient elution at a flow rate of 1.0 mL/min. The detection wavelength was set at 205, 250, 280, and 330 nm. The developed method had good linearity ($R^2$ > 0.9997) and the limit of detection (LOD) and limit of quantification (LOQ) were observed within the ranges 0.01~0.15 and 0.05~0.45 ${\mu}g/mL$, respectively. The relative standard deviation (RSD) values of intra- and inter-day testing were indicated that less than 3% and 90.31~103.31% of accuracy. The results of recovery test were 90.56~106.72% and RSD range was measured from 0.84 to 2.95%. In conclusion, this HPLC-DAD method has been successfully applied to the simultaneous determination of six compounds in Oryeongsan samples.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.25 no.2
• /
• pp.146-155
• /
• 2015

Objectives: The aims of this study were to set up benzene exposure matrices according to industry and process and to assess the risk of those occupational exposure to benzene. Methods: The benzene exposure matrices were assembled depending on industry and process, based on an exposure database provided by KOSHA(the Korean Occupational Safety and Health Agency), which was gathered from a workplace hazards evaluation program in Korea. These exposure matrices were assessed by Hallmark Risk Assessment tool. Results: The benzene was treated 412 industries sector(36%), 2,747 business places, and 471 industrial processes according to database. The arithmetic mean of past decade 8 hours time-weighted average of airborne benzene concentrations in the workplace was 0.10722 ppm. 1.07% of the total sample were greater than OEL, and 59.8% were showed less than the limit of detection. The highest risk values(Danger Value) were seen 36 industries including manufacture of general paints and similar product and 12 processes, such as other painting of manufacture of metal fabricated members. Exposure matrices based on employee exposure data base may provide exposure histories and can be used in epidemiological studies. Conclusions: It was found that more attentions should be paid to 36 among 412 industries and 12 of 471 processes, with a higher risk value.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.436-437
• /
• 2012

Double patterning technology (DPT) has been suggested as a promising candidates of the next generation lithography technology in FLASH and DRAM manufacturing in sub-40nm technology node. DPT enables to overcome the physical limitation of optical lithography, and it is expected to be continued as long as e-beam lithography takes place in manufacturing. Several different processes for DPT are currently available in practice, and they are litho-litho-etch (LLE), litho-etch-litho-etch (LELE), litho-freeze-litho-etch (LFLE), and self-aligned double patterning (SADP) [1]. The self-aligned approach is regarded as more suitable for mass production, but it requires precise control of sidewall space etch profile for the exact definition of hard mask layer. In this paper, we propose etch end point detection (EPD) in spacer etching to precisely control sidewall profile in SADP. Conventional etch EPD notify the end point after or on-set of a layer being etched is removed, but the EPD in spacer etch should land-off exactly after surface removal while the spacer is still remained. Precise control of real-time in-situ EPD may help to control the size of spacer to realize desired pattern geometry. To demonstrate the capability of spacer-etch EPD, we fabricated metal line structure on silicon dioxide layer and spacer deposition layer with silicon nitride. While blanket etch of the spacer layer takes place in inductively coupled plasma-reactive ion etching (ICP-RIE), in-situ monitoring of plasma chemistry is performed using optical emission spectroscopy (OES), and the acquired data is stored in a local computer. Through offline analysis of the acquired OES data with respect to etch gas and by-product chemistry, a representative EPD time traces signal is derived. We found that the SE-EPD is useful for precise control of spacer etching in DPT, and we are continuously developing real-time SE-EPD methodology employing cumulative sum (CUSUM) control chart [2].

• Korean Journal of Microbiology
• /
• v.43 no.3
• /
• pp.179-185
• /
• 2007

In this study, we used the method of guanidin isothiocyanate and boiling with Chelex-100 resin to extract genomic DNA of Ralstonia solanacearum from soil. It is more efficient than general protocols to remove inhibitory compounds in soil and R. solanacearum on. Then, we applied polymerase chain reaction and DNA enzyme-linked immunosorbent assay (ELISA) to identify and detect pathogen. The fliC gene of R. solanacearum was selected for specific detection of pathogen and primer sets were designed. Among the primer sets, two specific and sensitive primer sets, RsolfliC(forward: 5-GAACGCCAACGGTGCGAACT-3 and reverse; 5-GGCGGCCTTCAGGGAGGTC-3, designed by J. $Sch\ddot{o}nfeld$ et al.) and RS_247 (forward: 5-GGCGGTCTGTCGGCRG-3 and reverse; 5-CGGTCGCGTTGGCAAC-3 designed by this study), were designed to perform nested PCR. Nested PCR primer was labeled with biotin for hybridization between nested PCR product and probe to analyze with DNA ELISA.

• Applied Biological Chemistry
• /
• v.24 no.1
• /
• pp.29-39
• /
• 1981

Cooked spaghetti soaked in 10%, 20%, and 40% aqueous glycerine solutions for ten minutes absorbed sufficient glycerine to plasticize that spaghetti during and after subsequent drying. The plasticizing action of the glycerine prevented fissuring(checking) and surface corrugation of the spaghetti at elevated drying temperature and large wet-bulb dry-bulb temperature difference. The drying temperature and the wet-bulb dry-bulb differences up to which such protection was provided as the glycerine soak concentration increased. Despite the reduction in drying rate, the drying time required to produce spaghetti with a water activity of 0.65 (the level normally required for stability) decreased as glycerine content increased. At high frying temperatures glycerine addition increased the extent of browning and shortened the period required to induce detectale browning, but in all instances browning started well after the product $a_w$ reached the 0.65 value required for the completion of drying. Because glycerine addition reduced drying times at any given set of drying conditions and permitted the use of higher drying temperatures, relatively low levels of glycerine addition (e.g. 0.15 kg glycerine/kg dry spagetti) can shorten spagnetti drying times by roughly 80% and perhaps by as much as 93%.

• Korean Journal of Community Nutrition
• /
• v.13 no.1
• /
• pp.69-79
• /
• 2008

This study was designed to develop the strategy plans for the customer satisfaction on foodservice in the senior care facilities. For this, we examined the level of the customer satisfaction and foodservice quality. Additionally, the association between service quality, customer satisfaction, and social, psychological, physical factors of the aged were tested. Data from convenience samples from 3 senior care facilities were collected by using a questionnaire. Exploratory factor analyses were completed on 20 attributes for the food and service quality and 7 items for the social and psychological states of the aged, respectively. Cronbach's a was estimated for reliability, and Pearson correlation and multiple regression analysis were used for statistical analyses. The level of the satisfaction on foodservice was 4.01 of 5.0. The satisfaction on foodservice did not show the significant differences by gender, education level, BMI, and socio-psychological satisfaction. But the foodservice quality and the satisfaction showed significant difference by income and physical problem, and the goal of life of the eldely, respectively. Multiple regression analyses revealed that the determinants of the customer satisfaction on foodservice were the core quality of product, confidence, professionalism of employees and secondary quality of products. Especially, the kindness of employee is the most important attribute of the foodservice. Based on these results, we can set the strategy plans as follow: (1) the introduction of the foodservice evaluation system (2) the deployment of the event activities for offering fun to the customer (3) the continuous training of employees for ensuring the professional and kind service system, and (4) the introduction of selective menu system and take-out service of menu.