• Journal of Bio-Environment Control
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• v.2 no.2
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• pp.126-135
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• 1993

Recently, the characteristic of plant production systems in Korea has been changed with the strong trends of integration and large scale, using environmental control techniques. To satisfy this change successfully, first of all, the environmental prediction inside the system must be preceded. While many environmental prediction models for plant production system were developed by many persons, each model cannot be applied to the every situation without the perfect understanding of source codes and the technical modification. The purpose of this study is building the environmental prediction model to predict and evaluate the environment inside the system numerically, and also developing the multipurpose program available for practical design. The model consisted of the basic system model, the cultivation related model and the environmental control related model. The contents of each model are as follows : the basic system model is dealing with thermal and light environments, soil environment and ventilation : the cultivation related model with soil and hydroponic cultures ; and the environmental control related model with thermal curtain and heat exchanging system. The environmental prediction model was developed using a common simulation program, PCSMP, so that it could be easily understood and modified by anyone. Finally, the model was executed and verified through comparison between simulated and measured results for soil culture, and both results showed good agreements.

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.97-102
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• 2005

The addition reactions of $\alpha$,$\alpha$-difluoroiodomethyl n-butyl ketone, α,α-difluoroiodomethyl cyclohexyl ketone, or $\alpha$,$\alpha$-difluoroiodomethyl phenyl ketone to alkenes were successfully accomplished in good yields in the presence of copper powder. The reaction was also applicable to alkenes containing a variety of functional groups such as ester, trimethylsilyl, or ether group. Acetonitrile was determined to be the best solvent in the present study and the reaction was performed at 55 ${^{\circ}C}$ for 15-22 h. This reaction provides a new, efficient and general method for the synthesis of $\alpha$,$\alpha$-difluoro functionalized ketones.

• Resources Recycling
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• v.22 no.3
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• pp.81-90
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• 2013

Remanufacturing is one alternative to conserve the good environment of our earth and to save the production resources and manufacturing energy. To make active remanufacturing in Korea we have to prepare basic rules to support the collaboration among the original manufacturing, remanufacturing, and repairing companies. Basic rules for active remanufacturing can be established by the analysis of recently environments of remanufacturing procedures and the relationship among the main constituents.

• Journal of Ocean Engineering and Technology
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• v.35 no.2
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• pp.161-171
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• 2021

For the fatigue design of offshore structures, it is essential to understand and use the S-N curves specified in various industry standards and codes. This study compared the characteristics of the S-N curves for five major codes. The codes reviewed in this paper were DNV Classification Rules (DNV GL, 2016), ABS Classification Rules (ABS, 2003), British Standards (BSI, 2015), International Welding Association Standards (IIW, 2008), and European Standards (BSI, 2005). Types of stress, such as nominal stress, hot-spot stress, and effective notch stress, were analyzed according to the code. The basic shape of the S-N curve for each code was analyzed. A review of the survival probability of the basic design S-N curve for each code was performed. Finally, the impact on the conservatism of the design was analyzed by comparing the S-N curves of three grades D, E, and F by the five codes. The results presented in this paper are considered to be a good guideline for the fatigue design of offshore structures because the S-N curves of the five most-used codes were analyzed in depth.

• IMMUNE NETWORK
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• v.21 no.3
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• pp.21.1-21.22
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• 2021

Myeloid-derived suppressor cells (MDSCs) have strong immunosuppressive activity and are morphologically similar to conventional monocytes and granulocytes. The development and classification of these cells have, however, been controversial. The activation network of MDSCs is relatively complex, and their mechanism of action is poorly understood, creating an avenue for further research. In recent years, MDSCs have been found to play an important role in immune regulation and in effectively inhibiting the activity of effector lymphocytes. Under certain conditions, particularly in the case of tissue damage or inflammation, MDSCs play a leading role in the immune response of the central nervous system. In cancer, however, this can lead to tumor immune evasion and the development of related diseases. Under cancerous conditions, tumors often alter bone marrow formation, thus affecting progenitor cell differentiation, and ultimately, MDSC accumulation. MDSCs are important contributors to tumor progression and play a key role in promoting tumor growth and metastasis, and even reduce the efficacy of immunotherapy. Currently, a number of studies have demonstrated that MDSCs play a key regulatory role in many clinical diseases. In light of these studies, this review discusses the origin of MDSCs, the mechanisms underlying their activation, their role in a variety of clinical diseases, and their function in immune response regulation.

• Journal of Korean society of Dental Hygiene
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• v.9 no.4
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• pp.808-823
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• 2009

Objectives : This study was to suggest the basic data to develop the national exam contents for dental hygiene by comparing with those of other country. Methods : Several dental hygiene education course results were reviewed, and analyzed the culture subjects, basic major subjects, educational subjects, national exam contents in 3 or 4 years dental hygiene curriculum. Results : In Korea, grades of culture subjects in dental hygiene curriculum were different between 3 and 4 years education course, mean grades were 10.4, and 34.5 respectively. While there were few different between 3 and 4 years education course, mean grades were 36, and 36.5 respectively in foreign country. In Korea, grades of major subjects in dental hygiene curriculum were similar between 3 and 4 years education course as mean grades of 110, while there were different between 3 and 4 years education course, mean grades were 60 and 80 respectively in foreign country. In Korea, number of major subject was higher in 4 years(n=61) than 3 years(n=54). However, it was lower in 4 years(n=27) than in 3 years(n=33) in foreign country. Total grade number was 129 in 3 years, and 145 in 4 years in Korea, while it was 97 in 3 years, and 116 in 4 years in foreign country. By analyzing 3 years education course, culture subject was 9.5%, basic health was 11.2%, oral biology was 11.2%, clinical dentistry was 20.7%, public oral health was 10.4%, oral hygiene care was 35.9%, management of dental clinic was 9.4%, education was 2.8% in Korea. In USA, dental hygiene examination contains practice work as major part, while theory was thought of as most important things in korea. Conclusions : It is necessary to improve learning course of dental hygiene curriculum on the basis of other country's system, and then it could be possible to development of good quality's national examination contents, thus good quality of dental hygiene personnel would be turned out in Korea.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.168-168
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• 2010

Transparent conduction oxides (TCOs) films is extensively reported for optoelectronic devices application such as touch panels, solar cells, liquid crystal displays (LCDs), and organic light emitting diodes(OLEDs). Among the many TCO film, indium tin oxide(ITO) is in great demand due to the growth of flat panel display industry. However, indium is not only high cost but also its deposits dwindling. Therefore, many studies are being done on the transparent conductive oxides(TCOs). We fabricated a target of IZTO(In2O3:ZnO:SnO2=70:15:15 wt.%) reduced indium. Then, IZTO thin films were deposited on glass substrates by pulsed DC magnetron sputtering with various oxygen flow ratio. The substrate temperature was fixed at the room temperature. We investigated the electrical, optical, structural properties of IZTO thin films. The electrical properties of IZTO thin films were dependent on the oxygen partial pressure. As a result, the most excellent properties of IZTO thin films were obtained at the 3% of oxygen flow rate with the low resistivity of $7.236{\times}10^{-4}{\Omega}cm$. And also the optical properties of IZTO thin films were shown the good transmittance over 80%. These IZTO thin films were used to fabricated organic light emitting diodes(OLEDs) as anode and the device performances studied. The OLED with an IZTO anode deposited at optimized deposition condition showed good brightness properties. Therefore, IZTO has utility value of TCO electrode although it reduced indium and we expect it is possible for the IZTO to apply to flexible display due to the low processing temperature.

• Applied Microscopy
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• v.29 no.1
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• pp.67-73
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• 1999

It is practically hard to prepare good TEM specimens from powders which are embedded in epoxy materials for ion milling, because the milling rate difference between powders and epoxy is quite large. In order to overcome this problem, we tried to find methods to increase the density of powders in the embedding epoxy without loosing the adhesive strength between them. Powder density was considerably increased by employing a centrifuge for embedding, compared to the result by a conventional vacuum embedding. In addition, mixing powders of different sizes after sieving also enhanced the final density by allowing smaller particles filling in the gaps of larger particles. Ion milling of powders embedded by these methods resulted in thin specimens good enough for normal TEM works. TEM specimens from spherical, platy and fibrous powders of submicron size were successfully prepared by this centrifuging method.

• Human Ecology Research
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• v.60 no.1
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• pp.131-145
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• 2022

The purpose of this study was to reveal the effects of sales services and organizational member relationships of fashion brand salespersons on job performance and job satisfaction, as well as how job performance, job satisfaction, salesperson services, and organizational member relationships differ according to the sales career and job position. The data were collected by administering a questionnaire to fashion brand salespeople in Gwangju from September to October 2020. Using 235 responses, the data were analyzed with SPSS 27.0 for frequency analysis, reliability analysis, t-test, factor analysis, and regression analysis. The research results were as follows. First, the basic services of the salesperson comprised factors such as 'consideration and convenience', 'appearance and dress', and 'kindness and greeting', which are considered better variables to explain job performance than job satisfaction. Second, the salesperson's professional service consisted of 'fashion product knowledge', 'professional self-management', and 'store display technology' factors, which are good variables to predict job performance. Third, the relationship between the members of a salesperson's organization consists of factors such as 'headquarters relations', 'colleague relations', and 'emotional labor', which was better for explaining job satisfaction than job performance. Fourth, depending on the position, professional salespeople exhibited significantly higher values in job performance, basic and professional services of salespersons, and 'headquarters relations' factors, whereas there were no significant differences in job satisfaction, 'colleague relations' and 'emotional labor'. Lastly, the more sales career, the higher the job performance, and the basic services, professional services, and 'headquarters relations' factors of salespeople were also good.

• Journal of the Korean Society of Clothing and Textiles
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• v.42 no.4
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• pp.612-625
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• 2018

This study designed 16 kinds of basic structure and 4 kinds of modified structure for impact protection pads with a spacer fabric shape. The pad is a structure in which hexagonal three-dimensional units, composed of a surface layer and a spacer layer, are interconnected. Designed pads were printed with flexible $NinjaFlex^{(R)}$ materials using a FDM 3D printer. The printed pads were evaluated for impact protection performance, compression properties and sensory properties. The evaluation of the impact protection performance indicated that basic structures better than CR foam material at 20cm height were DV1.5, DX1.5, DX1.0, DV1.0 and HV1.5. The evaluation of the compression properties for the five types, with good results in the impact protection performance, indicated that DV1.0, DX1.0, DV1.5, HV1.5 and DX1.5 showed good results, respectively. The sensory evaluation of DV1.0, DX1.0, and DV1.5, which with good results when considering both the impact protection performance and the compression performance, showed that DV1.0 were the best for surface, flexibility, compression and weight. Therefore, DV1.0 is shown to be the best structure for protection pads.