• Analytical Science and Technology
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• v.36 no.4
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• pp.152-160
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• 2023

Adenosine and cordycepin are bioactive compounds with health benefits. Therefore, both substances are often used to assess the quality of Cordyceps products. Optimization and validation of the HPLC/DAD method for determining two nucleosides were studied. The samples were prepared using an ultrasound-assisted extraction (ultrasonic bath). The result was optimal conditions for aqueous extraction, an extraction time of 35 min, and an extraction temperature of 40 ℃. The Chromatographic separation was achieved using a reverse phase column (InfinityLab Poroshell 120 EC-C18, 4.6 × 250 mm, 2.7 ㎛) at 30 ℃ with a mobile phase gradient elution of water and methanol at a flow rate of 0.7 mL/min. The eluents were monitored via a diode array detector at 260 nm. Two nucleosides were separated by less than 12 min after injection. The developed method was found to be excellent linear (r² > 0.9999), accurate (% recovery 95.34-98.51), and precise (% relative standard deviation < 2.0). The limit of detection (LOD) and quantification (LOQ) were 0.45 and 1.38 mg/mL for adenosine and 0.47 and 1.43 mg/mL for cordycepin, respectively. This method was satisfactory for simultaneously quantitating two nucleoside contents, which were used to evaluate Cordyceps products.

• Journal of Korean Academy of Dental Administration
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• v.10 no.1
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• pp.76-83
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• 2022

This study was undertaken to confirm the relationship between the manner of focus and job performance of clinical dental hygienists. A survey was conducted, and the results of the survey were analyzed using multiple regression analysis. As a result, in the correlation between job performance ability and focusing manner and appreciation of the experience process, which are sub-factors of job performance ability and focusing manner, r=.161 (p<0.1) and appropriate distance r=.229 (p<0.1) indicated a positive (+) correlation. Multiple regression analysis revealed that the factors that have the greatest influence on job performance are type of workplace (β=-0.381), focusing attitude (β=0.166), marital status (β=-0.156), and age (β=0.152). Therefore, by confirming the relationship between focusing and job performance ability, we intend to provide the basic data necessary to prepare measures to improve dental hospital management and job performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.211-219
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• 2012

This study was performed to search for correlation between activity limitation level and participation restriction of children with cerebral palsy by investigating the activity limitation level through the use of the GMFCS E&R and the MACS and by figuring out participation restriction level through questionnaire survey. This study was performed, from May 1, 2010 to August 31, 2010, on 152 children with cerebral palsy ranging from 4 to 12 years, who are receiving rehabilitation therapy in the hospitals and community clinics in Busan and Gyeongnam province. The levels of activity limitation were assessed by using GMFCS E&R and MACS, and a questionnaire survey was conducted for participation restriction of the participating children. Spearman rank correlation was used for correlation analysis with the statistical software, SPSS 12.0. Majority of the children scored level 5 in both GMFCS E&R and MACS which is high frequency of activity limitation levels. Children in these levels also showed severe or complete participation restriction for mobility, education, and social relations. The analysis showed a significantly positive correlation between activity limitation level and participation restriction. Therefore this study may be useful in assessing the functional movement component of participation in children with cerebral palsy and developing the intervention plan for participation.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.149-152
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• 1984

Fifiy-five wheat samples were studied to obtain the basic information on the varietal differences of physicochemical characteristics and cookie baking potentiality in wheat breeding lines. Alkaline water retention capacity (AWRC) value had a correlation coefficient of $0.51^{**}$ with sedimentation value, of $0.45^{**}$ with protein content, and of $0.47^{**}$, with Pelshenke value. The highly significant correlation coefficient was obtained for cookie diameter vs. AWRC value $(-0.98^{**})$ and cooki diameter vs. protein content $(-0.46^{**})$. Farinograph absorption is highly correlated with AWRC value $(r=0.77^{**})$ and with cookie diameter $(r=-0.73^{**})$. Farinograph band width had a correlation coefficient of $-0.49^{**}$ with AWRC value, and of $0.44^{**}$ with cookie diameter.

• Journal of the Korean Society for information Management
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• v.5 no.1
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• pp.131-152
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• 1988

It is purposed in this paper to improve the retrieval cffect~venebs through the use of the seman-- t r knowledge of search terms in a computerbased search system. This study is developed it1 three stages include the experimentation of index terms or1 the probab~listir model, indexing with relational operators, and knowledgebase design. The sl~bject experimerltrd is the specific fklds of Chemical Engineering, ' Fluid Flow' and 'Combustion: As for the system ~rnplementatlon. two kinds of search method a r e done. Orie is to search terms related to one specialty word, the other is to retriele the articles based or1 the gueries.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.149-152
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• 2012

The (S)-(+)-decursin and its analogues are reported as potent inhibitors of melanin production in B16 murine melanoma cells. In order to understand the factors responsible for potency as well as inhibition of potency of (S)-(+)-decursin and its analogues, three-dimensional quantitative structure-activity relationship (3D-QSAR) studies were performed. Since receptor structures are not available, a pharmacophore model was constructed. Using PHASE, we generated 3 different models and selected the seven-site model, which returned excellent statistical values ($r^2$ = 0.9127, $Q^2$ = 0.6878, Pearson-R = 0.9014). Using the generated pharmacophore model, we screened a natural products library and obtained 4'-epi-decursin as the most related compound. 4'-epidecursin is similar to (S)-(+)-decursin, but shows additional interaction possibilities with tyrosinase. The study thus sheds some light on possibility of developing more potent tyrosinase inhibitors.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.145-152
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• 2000

A turbopump system composed of two pumps and one turbine is considered. The turbine composed of a nozzle and a rotor is used to drive the pumps while gas passes through the nozzle, potential energy is converted to kinematic energy, which forces the rotor blades to spin. In this study, an aerodynamic design of turbine system is investigated using compressible fluid dynamic theories with some pre-determined design requirements (i.e., pressure ratio, rotational speed, required power etc.) obtained from liquid rocket engine (L.R.E.) system design. For simplicity of turbine system, impulse-type rotor blades for open type L.R.E. have been chosen. Usually, the open-type turbine system requires low mass flow rate compared to close-type system. In this study, a partial admission nozzle Is adopted to maximize the efficiency of the open-type turbine system. A design methodology of turbine system has been introduced. Especially, partial admission nozzle has been designed by means of simple empirical correlations between efficiency and configuration of the nozzle. Finally, a turbine system design for a 10 ton thrust level of L.R.E is presented.

• Research in Plant Disease
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• v.11 no.2
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• pp.152-157
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• 2005

In a course of searching for biofungicide to control crisphead lettuce bottom rot caused by Rhizoctonia solani, we have isolated an antagonistic bacterium from lettuce rhisophere soil. A total of 702 bacterial isolates were isolated and tested for in vitro growth inhibition of R. solani. Seven strains appeared to have strong antagonistic effect against R. solani in in vitro growth inhibition assay. In the pot experiments, a strain BW-13 showed the most potent disease control effect on the both lettuce seedlings and adults plants. Therefore, the BW-13 was selected as a biocotrol candidate against crisphead lettuce bottom rot. Based on its morphology, physiological characteristics, and 165 rRNA gene analysis, the BW-13 was finally identified as Stenotrophomonas maltophilia. This study indicated that S. maltophilia BW-13 could be used as a biocontrol agent to control crisphead lettuce bottom rot.

• IEIE Transactions on Smart Processing and Computing
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• v.1 no.3
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• pp.152-160
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• 2012

This paper proposes a frame-level rate control algorithm for low delay video applications to reduce the fluctuations in the bitrate. The proposed algorithm minimizes the bitrate fluctuations in two ways with minimal coding loss. First, the proposed rate control applies R-Q model to all frames including the first frame of every group of pictures (GOP) except for the first one of a sequence. Conventional rate control algorithms do not use any R-Q models for the first frame of each GOP and do not estimate the generated-bit. An unexpected output rate result from the first frame affects the remainder of the pictures in the rate control. Second, a rate-distortion (R-D) cost is calculated regardless of the hierarchical coding structure for low bitrate fluctuations because the hierarchical coding structure controls the output bitrate in rate distortion optimization (RDO) process. The experimental results show that the average variance of per-frame bits with the proposed algorithm can reduce by approximately 33.8% with a delta peak signal-to-noise ratio (PSNR) degradation of 1.4dB for a "low-delay B" coding structure and by approximately 35.7% with a delta-PSNR degradation of 1.3dB for a "low-delay P" coding structure, compared to HM 8.0 rate control.

• Journal of the Korea Safety Management & Science
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• v.10 no.1
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• pp.59-65
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• 2008

Recently, obesity that is increasingly becoming a major cause of various diseases and safety accidents in work places is emerging as a serious social problem. It is due to economic growth and improvement of living environments. Many researches are trying to find the root cause of obesity. Thus, the main objective of this study is to analyze obesity index of citizens in Seoul which is a metropolis of Korea and a densely populated district. The data used in this study included 179 men and 152 woman subjects who are living in Seoul. Somatotype using $R\ddot{o}hrer$ Index can be classified by 3 types (thin, standard, obesity). In order to analyze a detailed somatotype of citizens, age groups are divided into $30{\sim}34,\;35{\sim}39,\;40{\sim}49,\;and\;50{\sim}59$ years according to gender, respectively. In order to compare and analyze data, Coefficient of Variance, Cronbach's Alpha, $R\ddot{o}hrer$ Idex and Drop Value were used in this study. The results of this study can be applied to the comfortable and safe work environments for workers.