• The Journal of the Korea Contents Association
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• v.9 no.2
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• pp.381-390
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• 2009

The study is intended to investigates any effective hotel employee's leadership on cohesiveness and trust. The results were as follows; First, hotel employee's leadership has correlation in trust and cohesiveness according to statistics. It should be interested in the leadership to display their potential ability and an initiative spirit in the organization. Second, trust has positive influence on the cohesiveness. The cohesiveness will has positive influence every organization so hotel employees should be interested in the result. Therefore, hotel employee should grasps a training system and recognition to apply their organization. According to the effective analysis, this study provides basic data about human resource management of the hotel but there is the limit in the study and it needs to study later. Because the subject is the hotel, it couldn't compare with other company so there is the limit to make generalization. Methodology in hypothesis only relies on the survey, using of a overseas scale and cross-section data should be studied to make generalization by a vertical study. Hereafter hotel employee's leadership is effected what factor is and the study should be achieved about specifical process and method to get the reliability to employees.

• Convergence Security Journal
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• v.5 no.1
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• pp.75-83
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• 2005

A purpose of the system proposed in this paper is to help learners pursue proactive and self-oriented education by allowing learners to proactively configure their own content, that is, learners no longer have to be restricted by prescribed sequence of lectures. In general, most LMSs cannot meet every individual's educational needs because they structure their programs by letting learners simply choose from a list of available lectures at prescribed level or difficulty. However the Self-Leading LMS eliminates such boundaries by allowing learners to choose contents and difficulty within the limit set by their own educational competence.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.203-208
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• 2010

In this study, the level of migration of 5 kinds of volatile organic compounds (VOCs) (toluene, styrene, ethylbenzene, isopropylbenzene and n-propylbenzene) into distilled water from polystyrene-made food containers was measured using Purge&Trap combined with GC/FID. The contents of the VOCs which have regulatory limits in Korea food code only for material specification were determined under three exposure conditions which were 30 min at $60^{\circ}C$, 30 min at $95^{\circ}C$ and actual situation of instant noodle intake. The calibration curve of 5 compounds showed good linearity ($^r2$ = 0.9976~0.9995) within the concentration range of 1~50 ng/mL. The limit of detection (LOD) and limit of quantification (LOQ) were validated at range of 0.041~0.092 and 0.135~0.304 ng/mL, respectively. The average migration contents of 5 compounds were below 5 ng/mL except for styrene. The average contents of styrene were highly detected at $95^{\circ}C$ for 30 min exposure (52.71 ng/mL). Under actual condition at instant noodle intake, the average contents of styrene was 17.23 ng/mL. The results demonstrated that the migration rate of VOCs was related to storage temperature and time.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.384-394
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• 2021

The aim of this study was to investigate the correlation between soil properties and marker compounds contents of Paeonia lactiflora. The methods of determining marker compounds were validated by measuring the linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy and recovery using UPLC analysis. P. lactiflora contained albiflorin at 0.04 ± 0.00 ~ 2.79 ± 0.21%, paeoniflorin at 1.98 ± 0.14 ~ 6.67 ± 0.84%. The root dry weight (RDW) of P. lactiflora was 0.06 ± 0.02 ~ 1.27 ± 0.28 kg. The soil properties analysis such as soil pH, electric conductivity (EC), organic matter (OM), total nitrogen (TN), available phosphate (Avail. P₂O₅), exchangeable cation and cation exchange capacity (CEC) were performed following standard analysis manual. The results of correlation analysis between soil properties and growth characteristics, available P₂O₅ was positively coreelated with the RDW of P. lactiflora. On the other hand, the RDW of P. lactiflora showed significantly negative correlation with contents of albiflorin and paeoniflorin. The results of this study was might be help to provide useful information on the establish of standard cultivation by the investigate correlation analysis between growth characteristics and marker compound contents of P. lactiflora.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.87-94
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• 2013

An analytical methodology based on solid-space extraction (SPE) with with Bond Elut Certify cartridge (Varian, 130 mg) has been developed for the qualification and quantitation of strychnine in blood. After the elution layer was evaporated, the residue was reconstituted with methanol for GC/MS. Internal standard was used 10 mg/l dextromethorphan. Strychnine is a potent central nervous stimulant and convulsant, and an alkaloid found in seeds of Strychnos nux-vomica. It was used therapeutically to improve circulation and muscle tone in oral or intramuscular doses of 0.05~8 mg. The fatal dose of strychnine for humans is 50~100 mg. A man was found dead lying curled up the corner of the large room in a roof house after the fire fighter opened a locked door inside to put out the fire. The postmortem blood and gastric contents were analyzed for toxicological testing. Strychnine and brucine were detected using GC/MS first in gastric contents extracts. The contents of strychnine was 0.083 mg/l in heart blood, 0.088 mg/l in peripheral blood and 4.0 mg/kg in gastric contents, respectively. Method validation was carried out in terms of linearity, accuracy, precision (intraday, interday) in blood. The assay is linear over 0.05~10 mg/l ($r^2$=0.999). Limit of detection (LOD) and limit of quantitation (LOQ) in blood were determined 0.02 mg/l (S/N=3) and 0.07 mg/l (S/N=10), respectively. Accuracy (bias%) of strychnine with 0.1, 1 and 10 mg/l was 12.0% (n=6), 9.3% (n=6) and 6.9% (n=6), respectively. Intraday precision (CV%) of strychnine with, 0.1, 1 and 10 mg/l were 6.4%, 10.4%, 1.2% (n=6), respectively. Interday precision (CV%) of strychnine with 0.1, 1 and 10 mg/l over three days were 24.0%, 18.5%, 13.8% (n=18), respectively. Relative recovery with 0.1, 1 and 10 mg/l (in blood) were 114.9%, 99.3% and 87.4% (n=6), respectively. The described method can be applied in forensic toxicology to determine strychnine in blood samples.

• Korean Journal of Pharmacognosy
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• v.48 no.1
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• pp.88-92
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• 2017

In the present study, we carried out quantitative analysis of chrysin and pinocembrin in Korean propolis by ultra performance liquid chromatography (UPLC) equipped with diode array detector. The separation was done using BEH C18 ($2.1{\times}50mm$, $1.7{\mu}m$) column with a mobile phase consisting of MeCN and 0.1% $H_3PO_4$ at 280 nm. The chromatographic method was validated for specificity, limit of detection, limit of quantification, linearity, precision, and accuracy. A quantitative analysis exhibited that the contents of the two compounds in Korean propolis collected from 8 inland areas except Jeju-do ranged from 3.1-46.0 mg/g. These results will be valuable as basic data for standardization of Korean propolis.

• Biomedical Science Letters
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• v.13 no.4
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• pp.361-368
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• 2007

Biological samples can be fixed either by chemical method by using chemical solution or physical methods by using heat treatment. The problem in traditional heat fixation is unsatisfactory quality due to uneven heat conduction in specimen and loss of inner cell contents. Chemical fixation method also bears several intrinsic problems like the limit in specimen size, time consumption in fixative impregnation, and loss of low molecular weight cell components. These factors deteriorate the quality of fixed specimen, thus limit the magnification and contrast of tissue pictures. Microwave heat has been reported to be a good alternative to current chemical methods to overcome these problem. In this study, we tried to introduce the microwave energy method to routine fixation work in hospital. We replaced chemical fixative with saline to provide moderate reaction condition, and used frozen section to reduce time for sample preparation. Temperature was measured at each experiment. The fixation of rat kidney tissue with 2.45 GHz electromagnetic wave and saline showed similar result to the control group fixed with traditional chemical method. Human tumor tissue fixed with 2.45 GHz electromagnetic in frozen section was improved in terms of histochemistry of PAS and immunohistochemistry of tumor marker like cytokeratin. Total turnaround time was reduced from $24\sim38$ h to to $2\sim4$ h. In conclusion, the quality of samples prepared by microwave heating method was at least as good as that of traditional method. If the condition for the fixation of different specimens is standardized, this new method could be applied to routine work in hospital, and could save working time as well.

• Steel and Composite Structures
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• v.49 no.5
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• pp.571-585
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• 2023

The application of relatively low volumes of fibres in normal strength concrete has been shown to be of significant benefit when applied to composite slabs with profiled sheet decking. This paper reports on an experimental study aimed at quantifying further potential benefits that may arise from applying ultra-high performance fibre reinforced concrete. To assess performance six simply supported beams were tested under hogging and sagging loading configurations along with three two span continuous beams. Fibre contents are varied from 0% to 2% and changes in strength, deformation, crack width and moment redistribution are measured. At the serviceability limit state, it is shown that the addition of high fibre volumes can significantly enhance member stiffness and reduce crack widths in all beams. At the ultimate limit state it is observed that a transition from 0% to 1% fibres significantly increases strength but that there is a maximum fibre volume beyond which no further increases in strength are possible. Conversely, member ductility and moment redistribution are shown to be strongly proportional to fibre volume.

• Toxicological Research
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• v.31 no.3
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• pp.265-271
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• 2015

This study was carried out to investigate contents of 8 polycyclic aromatic hydrocarbons (PAHs) from frequently consumed seafood and dairy products and to evaluate their chemical analysis methods. Samples were collected from markets of 9 cities in Korea chosen as the population reference and evaluated. The methodology involved saponification, extraction with n-hexane, clean-up on Sep-Pak silica cartridges and gas chromatograph-mass spectrometry analysis. Validation proceeded on 2 matrices. Recoveries for 8 PAHs ranged from 86.87 to 103.57%. The limit of detection (LOD) 8 PAHs was $0.04{\sim}0.20{\mu}g/kg$, and limit of quantification (LOQ) of 8 PAHs was $0.12{\sim}0.60{\mu}g/kg$. The mean concentration of benzo[a]pyrene (BaP) was $0.34{\mu}g/kg$ from seafood and $0.34{\mu}g/kg$ from dairy products. The total PAHs concentration was $1.06{\mu}g/kg$ in seafood and $1.52{\mu}g/kg$ in dairy products.

• Elastomers and Composites
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• v.37 no.3
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• pp.177-182
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• 2002

For low-smoke-type polyolefin compound, LDPE, EVA, and EEA as base resin, magnesium trihydrate, alumina trihydrate, and red phosphorous as flame retardant and MAH type compatibilizer were applied. The amount of each component was changed to find out optimum composition. Mechanical properties were obtained by tensile test and residual stress after aging and flame retardancy was evaluated by smoke density, LOI(Limit Oxygen Index), and UL-94 test. SEM was used for the investigation or morphology and halogen contents were obtained by measuring the amount of HCI. Two kinds of halogen free compositions for flame retardant and low smote resin were found and it is expected to be applied for various purposes.