• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.877-883
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• 2014

This study investigated the manufacturing conditions of apple vinegar with high acetic acid content following fermentation according to alcohol concentration without any nutrients. We compared and analyzed the quality characteristics of high acetic acid fermentation by varying the initial alcohol content (6%, 7%, 8%, and 9%). In the results, it was possible to manufacture high acetic acid vinegar with 12% titratable acidity and an alcohol content of 6% and 7%. Lower initial alcohol content was associated with higher yield due to a shorter lag phase. For quality characteristics of the high acetic acid apple vinegar, pH was 2.91~3.20, titratable acidity was 12.0%, and organic acid consisted of acetic acid, malic acid, critic acid and oxalic acids. Based on the results, high acetic acid apple vinegar was produced using a two stage fermentation process after alcohol fermentation but the further research is needed to reduce the time of fermentation in fed-batch culture for industrial use.

• Journal of Sensor Science and Technology
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• v.23 no.3
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• pp.185-191
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• 2014

The width of depletion region in a varactor diode can be modulated by varying a reverse bias voltage. Thus, the preferred characteristics of depletion capacitance can obtained by the change in the width of depletion region so that it can select only the desirable frequencies. In this paper, the TV tuner varactor diode fabricated by hyper-abrupt profile control technique is presented. This diode can be operated within 3.3 V of driving voltage with capability of UHF band tuning. To form the hyperabrupt profile, firstly, p+ high concentration shallow junction with $0.2{\mu}m$ of junction depth and $1E+20ions/cm^3$ of surface concentration was formed using $BF_2$ implantation source. Simulation results optimized important factors such as epitaxial thickness and dose quality, diffusion time of n+ layer. To form steep hyper-abrupt profile, Formed n+ profile implanted the $PH_3$ source at Si(100) n-type epitaxial layer that has resistivity of $1.4{\Omega}cm$ and thickness of $2.4{\mu}m$ using p+ high concentration Shallow junction. Aluminum containing to 1% of Si was used as a electrode metal. Area of electrode was $30,200{\mu}m^2$. The C-V and Q-V electric characteristics were investigated by using impedance Analyzer (HP4291B). By controlling of concentration profile by n+ dosage at p+ high concentration shallow junction, the device with maximum $L_F$ at -1.5 V and 21.5~3.47 pF at 0.3~3.3 V was fabricated. We got the appropriate device in driving voltage 3.3 V having hyper-abrupt junction that profile order (m factor) is about -3/2. The deviation of capacitance by hyper-abrupt junction with C0.3 V of initial capacitance is due to the deviation of thermal process, ion implantation and diffusion. The deviation of initial capacitance at 0.3 V can be reduced by control of thermal process tolerance using RTP on wafer.

• Journal of Ginseng Research
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• v.5 no.1
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• pp.8-23
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• 1981

Color is one of the most important quality factors of red ginseng (Hong-sam) which is processed from fresh ginseng (Panax ginseng C. A. Meyer). Therefore, a study of characteristics of browning mixtures of aqueous fresh ginseng extracts, factors which accelerate the browning of the aqueous extracts, and the antioxidant activity of the browning mixtures may contribute to the improvement of the color and other quality of red ginseng and other ginseng products such as ginseng extracts. In the present study, factors which affect the Maillard-type browning reaction of aqueous extracts of fresh ginseng roots were investigated firstly by adding various concentrations (0.001-0.5M) of arginine or glucose solutions, by varying the browning reaction temperatures and durations. Secondly, some characteristics such as brown color intensity, amounts of water-soluble and ether-soluble extracts, amounts of non-dialyzable materials, pH, viscosity, and reactivity with 2,2'- diphenyl -1 - picrylhydrazyl and antioxidant activity of the browning mixtures of the aqueous fresh ginseng extracts with small amounts of 0.1 M arginine, 0.1 M glucose, and distilled water at various browning temperatures and reaction time were studied. The results of the present study are as follows. 1. Color intensity (absorbance at 470 nm) of the browning mixtures was increased by adding various concentrations of arginine solution to the fresh ginseng extract, but the addition of the same amount of glucose solution did not increase the color intensity. 2 The amounts of water- or ether-soluble extracts, amounts of non-dialyzable materials were slightly greater in case of the browning mixtures of the fresh ginseng extract with 0.1M arginine solution than in case of the browning mixtures of the fresh ginseng extract with the same amount of 0.1 M glucose solution. In the process of the browning reaction, the pH of the browning mixtures of the fresh ginseng extract with 0.1 M arginine solution decreased slightly, while that of the browning mixtures with 0. 1 M glucose solution was almost constant. 3. The color intensity (absorbance at 470 nm) of the browning mixtures of the fresh ginseng extract with 0.1 M arginine or 0.1 M glucose solutions did not correlate well with the reducing power or the antioxidant power of the browning mixtures. The antioxidant activity of 90% ethanol extracts from the earlier stages of the browning mixtures of the fresh ginseng extract with the arginine solution was almost comparable to that of the 90% ethanol extracts from the later stages of the corresponding browning mixtures. The browning mixtures of only the fresh ginseng extract or of the fresh ginseng extract with the glucose solution showed considerable antioxidant activity, although both showed less brown color intensity than the fresh ginseng extract with he arginine solution.

• Archives of design research
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• v.12 no.4
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• pp.317-326
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• 1999

The Korean traditional color passed down over countless generations has surpassed both surpassed both time and space and continue today to breathe life into its people's everyday. In order to clarify the characteristics of Korean traditional color blue and red, we investigate the names of them and measured the color tones of textile remains in Chosun era. The characteristics of Korean traditional color blue and red have been surveyed by means of the examination of color names in many famous literatures in Chosun era. Korean terms for color tones were characterized by enormous variety of epithes crowned on them. The color names mentioned contain many unaccountable epithes which were characterized also deep colors and light colors were dominant in it. As a means of enhancing possibilities within limited colors, the commoners increased the names for varying tones of blue color group(32kinds) and red color group(40kinds). These "blue(indigo dyeing)' and 'red(safflower dyeing)' in Chosun era were shown very high frequency in use and the costume colors in Royal Court. With combination of these various blue and red colors they represented a thought of color based on Yinyang Theory and created a polished aesthetic taste. The color samples of textile remains in museum were measured and designated by Munsell color system and the ISCC-NBS color designation system. THe appeared rates were derived on Chosun era and features of colors using on the period were discussed. We aim to present specific recipes in indigo dyeing and safflower dyeing for using our apparel product and folk art.

• The KIPS Transactions:PartB
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• v.17B no.1
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• pp.69-78
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• 2010

Spectral modeling synthesis (SMS) has been used as a powerful tool for musical sound modeling. This technique considers a sound as a combination of a deterministic plus a stochastic component. The deterministic component is represented by the series of sinusoids that are described by amplitude, frequency, and phase functions and the stochastic component is represented by a series of magnitude spectrum envelopes that functions as a time varying filter excited by white noise. These representations make it possible for a synthesized sound to attain all the perceptual characteristics of the original sound. However, sometimes considerable phase variations occur in the deterministic component by using the conventional SMS for the complex sound such as whale sounds when the partial frequencies in successive frames differ. This is because it utilizes the calculated phase to synthesize deterministic component of the sound. As a result, it does not provide a good spectrum matching between original and synthesized spectrum in higher frequency region. To overcome this problem, we propose a modified SMS that provides good spectrum matching of original and synthesized sound by calculating complex residual spectrum in frequency domain and utilizing original phase information to synthesize the deterministic component of the sound. Analysis and simulation results for synthesizing whale sounds suggest that the proposed method is comparable to the conventional SMS in both time and frequency domain. However, the proposed method outperforms the SMS in better spectrum matching.

• Journal of KIISE:Information Networking
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• v.34 no.6
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• pp.493-504
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• 2007

With the advance and proliferation of computer and wireless network technology, it is common to access to network through the wireless network using mobile device. The ratio of using the streaming media out of many applications through the network is increasing not only in the wired network but also in the wireless network. The streaming media is much bigger than other contents and requires more network bandwidth to communicate and more computing resources to process. However the mobile devices have relatively poor computing resource and low network bandwidth. If the streaming media service is provided for mobile devices without any consideration about the network bandwidth and computing power, it is difficult for the client to get the service of high quality. Since especially mobile devices are supported with very limited energy capacity from the battery, the streaming media service should be adjusted to the varying energy state of mobile devices to ensure the complete playback of streaming media. In this paper, we propose a new method to guarantee the complete playback time of the streaming media for the mobile clients by dynamically controlling transmitted frame rate to the client according to the estimated available time of mobile device using battery model reflecting the characteristic of the battery. Since the proposed method controls the number of frames transmitting to the client according to the energy state of the mobile device, the complete playback time is guaranteed to mobile clients.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.329-335
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• 1999

The yield of oleoresin content and functionality of fresh garlic were compared according to varying extraction conditions by microwave-assisted extraction (MAE) and conventional extraction (CE) methods. When different extracting conditions were applied, there was no significant difference of extraction methods in the oleoresin content. However, in the case of the CE, the optimum extraction time was two hours, while the other was about five minutes which meant that the extraction time was shortened drastically. The electron donating abilities showed a similar level which was 64% by both methods, using water. And, in the case of ethanol extraction, it resulted 63% and 51% by CE and MAE, respectively. The nitrite scavenging effect diminished while pH was increasing and especially, in the case of pH 1.2, it showed a high elimination effect of more than 90%. There was no difference of extraction methods. The tyrosinase inhibitory effect was 47% and 60% by CE and MAE, respectively in the case of the water extract. The ethanol extract showed similar or a slight lower inhibition of 45% and 39%. The angiotensin I-converting enzyme inhibitory effect showed more powerful activity in the case of MAE extract than CE extract, but there was not an increase relating to reaction time of enzyme. Also, pyruvic acid content was $44.8\;and\;36.0{\mu}moles$ per one gram of a garlic by CE and MAE, respectively when water was used, and was $28.6\;and\;32.0{\mu}moles$ by CE and MAE when ethanol was used. Again, there was no big difference between CE and MAE methods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.263-269
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• 1997

To cope with increasing importance of water stress in food crop production, some physiological characteristics, their cultivar-differences and grain yield of winter barley cultivars in response to water stress during reproductive stages were studied employing three covered-barley cultivars, Milyang 12, Durubori, and Olbori, one naked-barley cultivar, Baegdong, and one two-row malting-barley cultivar, Hyangmaeg. The barley grown in pot-soil was conditioned for 10 days under water stress, varying the time of water stress : 20 days before heading, 10 days before heading and the time of heading. The decrease in growth due to water stress varied greatly with the cultivars and time of water stress. The greatest injury occurred when water stress was imposed for 10 days from 10 days before heading : the culm length of water-stressed plants have shown reduced by 85∼98％ of the non-stressed; the number of spikes per plant by 52∼83%; the number of grains per spike by 71∼86%; 1,000-grain weight by 80∼84%; yield per pot by 60∼94%. The number of spikes per plant as one of yield components was most sensitively affected. As a whole, the drought resistance of cultivars was high in the order of Olbori> Milyang 12 and Durubori> Hyangmaeg>Baegdong. On rewatering the plants after termination of the water stress treatment the recovery rate of free proline content and relative turgidity of flag leaf were higher in 3 covered-barley cultivars, and lower in cultivars Baegdong and Hyangmaeg.

• The Journal of the Acoustical Society of Korea
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• v.41 no.6
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• pp.610-620
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• 2022

An acoustic vector sensor can simultaneously receive vector quantities, such as particle velocity and acceleration, as well as acoustic pressure at one location, and thus it can be used as a single input multiple output receiver in underwater acoustic communication systems. On the other hand, vector signals received by a single vector sensor have different channel characteristics due to the azimuth angle between the source and receiver and the difference in propagation angle of multipath in each component, producing different communication performances. In this paper, we propose a channel parameter-based weighting method to improve the performance of an acoustic communication system using a single vector sensor. To verify the proposed method, we used communication data collected from the experiment conducted during the KOREX-17 (Korea Reverberation Experiment). For communication demodulation, block-based time reversal technique which is robust against time-varying channels were utilized. Finally, the communication results showed that the effectiveness of the channel parameter-based weighting method for the underwater communication system using a single vector sensor was verified.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.640-645
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• 1995

Job's-tears(Coix lachryma-jobi L. var. Ma-yuen Stapf) seeds were processed to flakes by soaking, heat treatment, intermediate-moisture drying, flaking, drying, and cooking. Some functional properties of job's-tears flakes subjected to varing degree of heating were characterized by specific volume, texture, water absorption index(WAI), water solubility index(WSI), and viscosity. As degree of gelitinization increased within the intermediate range of $60{\sim}70%$, steam-cooked Job's-tears demonstrated appropriate rheological properties for further processes, resulting in increased specific volume and decreased breaking strength. However, excessive heat treatment rendered Job's-tears undesirably sticky for flaking, which caused adverse effects on the functional properties of flakes such as specific volume and breaking strength. Increasing steaming time$(5{\sim}30\;min)$ caused an increase in WAI and WSI values. Apparent viscosity of powdered flakes was increased with the extent of gelitinization as a function of heat processing. Viscosity of powdered flakes determined using the amylograph increased with the degree of heating applied to Job's-tears at low pasting temperatures, accompanied by a decrease in maximum viscosity as the pasting temperature increased.