• Preventive Nutrition and Food Science
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• v.22 no.1
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• pp.37-44
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• 2017

Sulfur-containing amino acids play important roles in good flavor generation in Maillard reaction of non-enzymatic browning, so aqueous model systems of glucosamine and cysteine were studied to investigate the effects of reaction temperature, initial pH, reaction time, and concentration ratio of glucosamine and cysteine. Response surface methodology was applied to optimize the independent reaction parameters of cysteine and glucosamine in Maillard reaction. Box-Behnken factorial design was used with 30 runs of 16 factorial levels, 8 axial levels and 6 central levels. The degree of Maillard reaction was determined by reading absorption at 425 nm in a spectrophotometer and Hunter's L, a, and b values. ${\Delta}E$ was consequently set as the fifth response factor. In the statistical analyses, determination coefficients ($R^2$) for their absorbance, Hunter's L, a, b values, and ${\Delta}E$ were 0.94, 0.79, 0.73, 0.96, and 0.79, respectively, showing that the absorbance and Hunter's b value were good dependent variables for this model system. The optimum processing parameters were determined to yield glucosamine-cysteine Maillard reaction product with higher absorbance and higher colour change. The optimum estimated absorbance was achieved at the condition of initial pH 8.0, $111^{\circ}C$ reaction temperature, 2.47 h reaction time, and 1.30 concentration ratio. The optimum condition for colour change measured by Hunter's b value was 2.41 h reaction time, $114^{\circ}C$ reaction temperature, initial pH 8.3, and 1.26 concentration ratio. These results can provide the basic information for Maillard reaction of aqueous model system between glucosamine and cysteine.

• Bulletin of the Korean Chemical Society
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• v.26 no.3
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• pp.428-432
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• 2005

Squarylium or squaraine dyes are derived from 1,2-dihydroxycyclobuten-3,4-dione, otherwise known as squaric acids. They are two principal types: the 1,2-bisdonorsubstituted derivatives, and the 1,3-bisdonorsubstituted derivatives. The former are essentially merocyanines and have no distinctive properties, whereas the latter represent a unique type of chromophore, which is neither a merocyanines nor cyanine and has exceptional light absorption characteristics. They also have many functional applications based on their special properties. Thus it was the objective of this research project to synthesize a range of 1,3-squarylium dyes of widely differing structural types, and to investigate their light absorption and fluorescence properties in general, and the color change properties of appropriate examples in particular. Also in this study, the various pHinduced colour change processes were examined.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1255-1272
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• 2023

Satellite-based chlorophyll-a concentration, produced as a long-term time series, is crucial for global climate change research. The production of data without gaps through the merging of time-synthesized or multi-satellite data is essential. However, studies related to satellite-based chlorophyll-a concentration in the waters around the Korean Peninsula have mainly focused on evaluating seasonal characteristics or proposing algorithms suitable for research areas using a single ocean color sensor. In this study, a merging dataset of remote sensing reflectance from the geostationary sensor GOCI-II and polar-orbiting sensors (MODIS, VIIRS, OLCI) was utilized to achieve high spatial coverage of chlorophyll-a concentration in the waters around the Korean Peninsula. The spatial coverage in the results of this study increased by approximately 30% compared to polar-orbiting sensor data, effectively compensating for gaps caused by clouds. Additionally, we aimed to quantitatively assess accuracy through comparison with global chlorophyll-a composite data provided by Ocean Colour Climate Change Initiative (OC-CCI) and GlobColour, along with in-situ observation data. However, due to the limited number of in-situ observation data, we could not provide statistically significant results. Nevertheless, we observed a tendency for underestimation compared to global data. Furthermore, for the evaluation of practical applications in response to marine disasters such as red tides, we qualitatively compared our results with a case of a red tide in the East Sea in 2013. The results showed similarities to OC-CCI rather than standalone geostationary sensor results. Through this study, we plan to use the generated data for future research in artificial intelligence models for prediction and anomaly utilization. It is anticipated that the results will be beneficial for monitoring chlorophyll-a events in the coastal waters around Korea.

• 보존과학연구
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• s.32
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• pp.37-52
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• 2011

This study investigates the hardening characteristics of the mixture lacquer and glue at room temperature. Diverse samples were made from manufacturing of glue to the adding ratio in sap of the lacquer tree. After the examination of moisture content of samples, it has been seen that there is no relation with glue's kinds or adding ratio, but only with contain level of moisture. The samples made with film shape in order to examine the drying time. Samples with isinglass needed for over three days and had smooth surface. However, samples mixed with animal glue dried within a day and had ripples on the surface because of fast drying rate. In addition, the samples with isinglass had slow change of colour in early step of drying and no colour difference after completely drying although it had significant changes to black oxide as soon as contact with air. In structural analysis with FT-IR showed that the carbonyl bond increased in the samples of mixed with glue, compared to raw lacquer and treated lacquer.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.10-16
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• 2020

Deterioration of reinforced concrete structure caused by chloride ingress is the main issue and regrading this, many studies have been investigated with both experiments and computational modelling. In addition to chloride diffusion, chloride sorption should be considered as a chloride transport mechanism in concrete structure and cracks formed in concrete structures are the main variable to evaluate the performance of the structures. In this study, after making two types of cracks width (0.1 and 0.3 mm) in reinforced concretes, chloride absorption tests were performed. Weight change and colour change using 0.1 AgNO3 solution from the samples were performed to measure chloride ingress. Image processing was also carried out to quantify range of colour change in carck face. From the result, it were confirmed that the amount of chloride absorption increases with exposure time and increasing crack width, and chlorides reached at steel depth within 1 hour. It would be possible that chloride can move through interface bewteen steel and concrete, thereby further study regarding this is required.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.199-204
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• 2011

This experiment was carried out to investigate the growth responses of zoysiagrass (Zoysia japonica Steud.) as affected by prohexadione-calcium foliar application for the effective labour saving and cost down management in the lawn yard, field and golf course etc. The leaf growth of zoysiagrass treated with prohexadione-calcium one day after mowing was significantly slow compared to the untreated plot. And the effect was continued up to 50 days. The growth inhibition rate at the treated plot was 46 to 50% compared to untreated plot and the leaf widths treated with prohexadione-calcium were narrower than control plot. The change of leaf dry weight 10 days after prohexadione-calcium treated was significantly shown less speedy than untrated plot and the results were continued up to 40 days after application. The SPAD values of the leaf colour were increased in the treated plots and continued for 40 days more.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.95-99
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• 2007

This study performed apreliminary test with male high school students in Gwangju metropolitan city in order to determine visual function information of high school students. For the items in this preliminary test, there were inquiry, test for long distance unaided visual acuity, pinhole visual acuity test, colour vision test, cover test and stereo test. Most complaint related to eye was about blurred vision (28.4%) and over 90% of subjects had one or more, and among them, over 50% appealed two or more complaints. 76.1% of all subjects showed less than 0.7 in unaided distance visual acuity. In pinhole visual acuity test, 98% had an improved unaided pinhole visual acuity and most of them experienced an improvement and 2% had no change or dropped. The students with normal stereoscopic vision test were 85.6% and the students under normal range were 14.4%. In colour vision test, 7.9% of them were protanomaly and deuteranomaly and none of them had trichromasy and total color blindness. In cover test, it showed 30.2% of orthophoria, 8.2% of esophoria and 61.5% of exophoria, and none of them had strabismus.

• Archives of design research
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• v.11 no.2
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• pp.31-45
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• 1998

Human beings receive experiences and education in viewing and manipulating objects since birth, These experiences in forms and colours influence signifrcantty the formation of the person's humanity, sensibility and constituOOn until he becomes an adult. Considering that all objects coexist through space and time with human beings from birth to an adulthood, we can imagine how these things shape a person, Human beings' perception of form and colour might be different according to the person's living environment, experiences, education, age and job, However, when we see there are certain kinds of form and colour of that most people favor, we can understand that human beings have a certain inherent feelings about forms and colours, Let's suppose a man faces an object that dosen't correspond with his basic feelings about form and colour, He would avoid that object at least unconsoousty, All of his acts dealing with form and colour probably satisfy a desire for beauty which can be required from certain proper forms and colours, By revealing the feelings about forms and colours that human beings originally have, this study is going to explore what kinds of form and colour have what kinds of psychological and physical influences on human beings. Another purpose of this study is to be a theory suggesting more profitable and effective forms and colours psychologically and physically to the consumer. this study demonstrates that the basic feelings about forms and colours which human beings possess are different according to the individual's psychology and the body's condition. It also establishes the reality of the principle of how human psychology and the body change according to the surrounding environment. Finally, it will be appropriate for the suggested theory from this study to be used as fundamental material in deciding the forms and colours used in the design field in the future in that these forms and colours are more profitable and efftient.

• Journal of Biomedical Engineering Research
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• v.15 no.2
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• pp.129-134
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• 1994

In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Transformation from temporal summation to two-dimensional mappings is formed by 4 nearest point interpolaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality.

• Journal of the Korean Solar Energy Society
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• v.35 no.3
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• pp.81-91
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• 2015

LED has received intensive research attention due to its long life, high efficacy, fast response and wide colour availability, and has secured extensive application areas. However, LED chips within the modules convert only fraction of electric energy into light, and majority of supplied energy needs to be dissipated as heat, which challenges in the performance and life of the LED modules. IEC 62717 specifies the performance requirements for LED modules together with the test methods and conditions. The present study examined the influence of different design parameters on performance temperature through series of experiments and numerical simulations. The economic means to change the module performance temperature during the measurement of mandatory markings were suggested based on predicted cooling performances.