• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.341-347
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• 1998

To develop simple and accurate analytical method for freezing time prediction of beef and tylose under various freezing conditions, freezing time (Y) was regressed against the reciprocal $(X_3)$ of difference of initial freezing point and freezing medium temperature, reciprocal $(X_4)$ of surface heat transfer coefficient, the initial temperature $(X_1)$ and thickness $(X_2)$ of samples which should cover most situations arising in frozen food industry. As results of the multiple regression analysis, equations were obtained as follows. $Y_{tylose}=3.45X_1+7642.84X_2+4642.67X_3+2946.89X_4-431.33\;(R^2=0.9568)$ and $Y_{beef}=0.68X_1+7568.98X_2+2430.78X_3+3293.26X_4-299.00\;(R^2=0.9897)$. These equations offered better results than Plank, Nagaoka and Pham's models, shown in satisfactory agreement with models of Cleland & Earle and Hung & Thompson when were compared to previous models, and the accuracy of its was very high as average absolute difference of about 10% in the difference between the fitted and experimental results. Also, thermal diffusivities of beef and tylose were measured as $4.43{\times}10^{-4}m^2/hr$ and $4.39{\times}10^{-4}m^2/hr$ at $6{\sim}7^{\circ}C$, $2.42{\times}10^{-3}m^2/hr$ and $3.32{\times}10^{-3}m^2/hr$ at $-10{\sim}-12^{\circ}C$. Initial freezing points of beef and tylose were $-1.2^{\circ}C\;and\;-0.6^{\circ}C$, respectively. Surface heat transfer coefficients were estimated $20.57\;W/m^2^{\circ}C$ with no-packing, $16.11\;W/m^2^{\circ}C$ with wrap packing and $13.07\;W/m^2^{\circ}C$ with Al-foil packing, and the cooling rate of immersion freezing method was about 10 times faster than that of air blast freezing method.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.5
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• pp.501-512
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• 2016

The study evaluated methods to measure condensable fine particles in flue gases and measured particulate matter by fuel and material to get precise concentrations and quantities. As a result of the method evaluation, it is required to improve test methods for measuring Condensable Particulate Matter (CPM) emitted after the conventional Filterable Particulate Matter (FPM) measurement process. Relative Standard Deviation (RSD) based on the evaluated analysis process showed that RSD percentages of FPM and CPM were around 27.0~139.5%. As errors in the process of CPM measurement and analysis can be caused while separating and dehydrating organic and inorganic materials from condensed liquid samples, transporting samples, and titrating ammonium hydroxide in the sample, it is required to comply with the exact test procedures. As for characteristics of FPM and CPM concentrations, CPM had about 1.6~63 times higher concentrations than FPM, and CPM caused huge increase in PM mass concentrations. Also, emission concentrations and quantities varied according to the characteristics of each fuel, the size of emitting facilities, operational conditions of emitters, etc. PM in the flue gases mostly consisted of CPM (61~99%), and the result of organic/inorganic component analysis revealed that organic dusts accounted for 30~88%. High-efficiency prevention facilities also had high concentrations of CPM due to large amounts of $NO_x$, and the more fuels, the more inorganic dusts. As a result of comparison between emission coefficients by fuel and the EPA AP-42, FPM had lower result values compared to that in the US materials, and CPM had higher values than FPM. For the emission coefficients of the total PM (FPM+CPM) by industry, that of thermal power stations (bituminous coal) was 71.64 g/ton, and cement manufacturing facility (blended fuels) 18.90 g/ton. In order to estimate emission quantities and coefficients proper to the circumstances of air pollutant-emitting facilities in Korea, measurement data need to be calculated in stages by facility condition according to the CPM measurement method in the study. About 80% of PM in flue gases are CPM, and a half of which are organic dusts that are mostly unknown yet. For effective management and control of PM in flue gases, it is necessary to identify the current conditions through quantitative and qualitative analysis of harmful organic substances, and have more interest in and conduct studies on unknown materials' measurements and behaviors.

• Journal of Astronomy and Space Sciences
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• v.22 no.3
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• pp.329-352
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• 2005

Long term observations of full-disk Lyman-o irradiance have been made by the instruments on various satellites. In addition, several sounding rockets dating back to the 1950s and up through the present have measured the $Lyman-{\alpha}$ irradiance. Previous full disk $Lyman-{\alpha}$ images of the sun have been very interesting and useful scientifically, but have been only five-minute 'snapshots' obtained on sounding rocket flights. All of these observations to date have been snapshots, with no time resolution to observe changes in the chromospheric structure as a result of the evolving magnetic field, and its effect on the Lyman-o intensity. The $Lyman-{\alpha}$ Imaging Solar Telescope(LIST) can provide a unique opportunity for the study of the sun in the $Lyman-{\alpha}$ region with the high time and spatial resolution for the first time. Up to the 2nd year development, the preliminary design of the optics, mechanical structure and electronics system has been completed. Also the mechanical structure analysis, thermal analysis were performed and the material for the structure was chosen as a result of these analyses. And the test plan and the verification matrix were decided. The operation systems, technical and scientific operation, were studied and finally decided. Those are the technical operation, mechanical working modes for the observation and safety, the scientific operation and the process of the acquired data. The basic techniques acquired through the development of satellite based solar telescope are essential for the construction of space environment forecast system in the future. The techniques which we developed through this study, like mechanical, optical and data processing techniques, could be applied extensively not only to the process of the future production of flight models of this kind, but also to the related industries. Also, we can utilize the scientific achievements which are obtained throughout the project And these can be utilized to build a high resolution photometric detectors for military and commercial purposes. It is also believed that we will be able to apply several acquired techniques for the development of the Korean satellite projects in the future.

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.95-102
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• 2016

This study investigated the growth characteristics of juvenile abalone when has been rearing as other different feed rates by the commercial abalone formulated feed on indoor tank, during the winter period that was maintaining on the low water temperature. Experimental abalones were use to 1 year old (shell length $29.14{\pm}2.56mm$, wet weight $2.9{\pm}0.6g$), and it has cultured at six feeding rate groups (0.75 DFW, 1.50 DFW, 2.25 DFW, 3.00 DFW, 3.75 DFW, 4.5 DFW) that were set up the daily feeding rate about total weight (DFW), and two replicated. The average water temperature in the experiment period was $9.7{\pm}3.27^{\circ}C$. In the monthly change absolute growth rate (AGRSL) and specific growth (SGRSL) of shell length, at January, 3.00 DFW was significantly higher than all feeding rate groups (P < 0.05). And in the monthly change of weight change and weight gain (WG), at March, 3.75DFW was significantly higher than all feeing rate groups (P < 0.05). The growth coefficient of thermal units (TGC) was decreased rapid since January, and 3.75 DFW was show significantly higher than all feeding rate groups (P < 0.05). In monthly change of feed efficiency (FE), at December, the 0.75 DFW was significantly higher than all feeding rate groups (P < 0.05), and in February and March, there was no significant difference between all feeding period. Therefore, In this study, was show that juvenile abalones can do to maintain or increasing from weight to supply commercial artificial diet during winter period when rearing into the indoor tank.

• The Korean Journal of Ecology
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• v.25 no.3 s.107
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• pp.163-170
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• 2002

In order to analyze the life cycle of A. artemisiifolia var. elatior dormancy and some environmental factors inducing germination of the seeds were examined. The results were as follows : Dormancy of fertile seeds was broken in part within a month after seed collection in case of adequate moisture and alternating temperature was also effective in breaking dormancy. The temperature range, which allow germination was $12^{\circ}C{\sim}32^{\circ}C$. Optimum temperature for germination was $24^{\circ}C$. The seed of A. artemisiifolia var. elatior was light-independent. The difference of storage period appeared to have no particular effect on the viability of seeds at any time during the 9-month storage period. In the increasing temperature(IT) regime, A. artemisiifolia var. elatior seeds started to germinate at $16^{\circ}C$, showing the higher temperature the greater germination rate : the final germination percentage was 99.34%. On the other hand, in the decresing temperature(DT) regime, seeds began to germinate at $20^{\circ}C$ with the 1.34% germination. An induced dormancy occurred at $12^{\circ}C$ making the 5.34% final germination in the DT regime. Low temperature was more effective to break dormancy than higher temperature. Seeds of A. artemisiifolia var. elatior seems to be germinated in mid to late autumn or germination delayed until following spring. The above results suggest these variation of germination response in diverse environmental factors seems to be a physiological strategy to maintain their existence and to reproduce in the extreme thermal variation.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.682-692
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• 2013

We investigated out the effect of cultivation region on the physicochemical characteristics of starch in six sweetpotato cultivars. The following sweetpotato cultivars were analyzed: Daeyumi, Shingeonmi, Jinhongmi, Shinyulmi, Yulmi, and Yeonhwangmi. Samples were cultivated in Muan, Iksan, Nonsan, Boryeong and Hamyang. The soil texture was found to be sandy loam in Muan, Iksan, and Boryeong, sandy clay loam in Nonsan, and loam in Hamyang. The starch content of the sweetpotato was higher in Muan than in Hamyang. The amylose content was 22.3-30.9%, and the highest amylose content was found in samples from Iksan. Rapid viscosity analysis showed that the samples from Hamyang had the lowest values of pasting temperature, while samples of the Daeyumi cultivar had the highest values. Thermal analysis with a differential scanning calorimeter showed that the Muan samples had the highest values of onset temperature, maximum peak temperature, and completion temperature, and the samples from Hamyang had the lowest values. There was no difference between the cultivation regions or the cultivar in the X-ray pattern of the starch or its appearance in scanning electron micrographs. Therefore, the results of this study confirm that cultivation region and cultivar play an important role in determining the quality of sweetpotato and the physicochemical characteristics of sweetpotato starch.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.123-129
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• 1991

The skipjack and Alaska pollack meat were packed in square No. 3B can, and thermally processed at $121.1^{\cir}C$ so far as to reach Fo values of 5, 10 and 20, respectively. Also the another samples which were heated at $98^{\cir}C$ for 30 minutes were prepared. We have examined the changes of nitrogenous extractives and texture by thermal processing at high temperature in both fish meats. Moisture contents of both fish meats decreased slightly with the increasing of Fo values. When the samples were heated at $98^{\cir}C$ and $121.1^{\cir}C$, pH and VBN contents increased markedly in both fish meats; increasing ratio of pH and VBN contents in skipjack meat was larger than those of Alaska pollack meat. Histamine were detected in concentration of 6.1mg/100g, 0.1mg/100g in raw skipjack and Alaska pollack meat, 8.2mg/100g, 0.1mg/100g in Fo 20 samples of these fish meats, respectively. The contents of total free amino acids in skipjack and Alaska polack meat were 984.8mg/100g, 282.3mg/100g, and these total contents decreased slightly with increasing of Fo values. Little changes were observed in free amino acid composition, but only His, Tau, Ala in skipjack meat and Tau in Alaska pollack meat decreased significantly by heat treatment. Also the degredation of IMP were Proceeded during Preparation and heat treatment of samples, and TMAO changed into TMA almost equivalently. In changes of textures, as compared with heating of 98t for 30 minutes; Fo 5 heat treatment became more softened these fish meats.

• Journal of Chest Surgery
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• v.37 no.1
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• pp.64-71
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• 2004

Background: Video-assisted sympathicotomy is a safe and effective method for the treatment of essential hyperhidrosis with immediate symptomatic improvement. However, this is offset by the occurrence of a high rate of side-effects, such as embarrassing compensatory hyperhidrosis. Therefore, by comparing and assessing the relationship between temperature change measured by DITI (digital infrared thermographic imaging) and clinical results according to the level and extent of sympathicotomy in essential hyperhidrosis. we tried to obtain a more precisely and objectively, the distribution and degree of compensatory sweating by DITI and also for ascertaining the clinical usefulness. Material and Method: From January 2000 to June 2002, the thoracoscopic sympathicotomy was performed in 28 patients suffering from essential hyperhidrosis in Dept. of Thoracic and Cardiovascular Surgery, Wonkwang University Hospital. The patients were divided into four groups, Group I: patients having undergone T2 sympathicotomy, Group II: patients having undergone T3 sympathicotomy, Group III: patients having undergone T3,4 sympathicotomy, and Group IV: patients having undergone T2,3,4 sympathicotomy. The parameters were composed of the satisfaction rate of treatment, the degree of compensatory and plantar sweating, and temperature changes of entire body measured by DITI Result: There was no difference in age and follow-up period among the groups. All of the treated patients obtained satisfactory alleviation of essential hyperhidrosis in immediate postoperative period. However, the rate of long-term satisfaction were 85.8%, 85.8%, 42.9%, and 28.6% in group I, II, III, and IV (p<0.05). More than embarrassing compensatory sweating was present in 14.2%, 14.2%, 57.1%, 71.4% in group I, II, III, and IV (p<0.05) In regard to plantar sweating, decrease in sweating was expressed in each of four groups, but was not significant between groups. An apparent increase of temperature measured by DITI indicated sufficient denervation and predicted long-lasting relief of essential hyperhidrosis and also decrease in temperature of trunk and lower extremity by DITI had correlated well with postoperative satisfaction, and also postoperative compensatory sweating. Conclusion: We suggested that the incidence and degree of compensatory sweating was closely related to the site and the extent of thoracic sympathicotomy. Resection of the lower interganglionic neural fiber of the second thoracic sympathetic ganglion on the third rib is the most practical and minimally invasive treatment than other surgical methods. We were also to anticipated the distribution and degree of compensatory sweating by DITI precisely and objectively and for ascertaining the clinical usefulness.

• Korean journal of food and cookery science
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• v.31 no.3
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• pp.304-317
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• 2015

For the production of pumpkin paste with respect to heating conditions, we steamed the pumpkin for roughly 15 min, heated it with high pressure treatment for 0 min (A), 10 min (B), 20 min (C), 40 min (D), and subsequently investigated the quality characteristics. Generally a significant difference was observed between the pumpkin paste treated with and without high-pressure heat. The values of water content, crude protein and crude fiber of the high-pressure heat-treated groups B, C, D were decreased compared with untreated group A. The soluble fiber in experimental group B sweet-pumpkin paste treated with high-pressure heat for 20 min was higher than the control, and the highest value at 2.02. Experimental group D sweet-pumpkin paste treated with high-pressure heat for 40 min was found to have a decreased soluble fiber content relative to the control. The L value for the color of the group A untreated control sweet-pumpkin paste (no high-pressure heating) decreased as the time increased from 10 min to 40 min, with L values of 50.33, 49.46, and 48.06, respectively. The b value for the color of the sweet-pumpkin paste also decreased, showing a significant difference. Taking into account all the results, we chose experimental group B in order to prepare sweet-pumpkin latte. We used 0.2% gum (xanthan gum, locust bean gum, guar gum) as a stabilizer. Sweet-pumpkin latte with xanthan and locust bean gum has a suspension stability effect that lasts 90 min. The L and b values of sweet-pumpkin latte with gums increase and a value decrease compared with the control. In terms of the overall acceptance of the sweet-pumpkin latte, the experimental group with xanthan gum scored the best.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.4
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• pp.176-184
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• 2011

Cold air on sloping surfaces flows down to the valley bottom in mountainous terrain at calm and clear nights. Based on the assumption that the cold air flow may be the same as the water flow, current models estimate temperature drop by regarding the cold air accumulation at a given location as the water-like free drainage. At a closed catchment whose outlet is blocked by man-made obstacles such as banks and roads, however, the water-like free drainage assumption is no longer valid because the cold air accumulates from the bottom first. We developed an empirical model to estimate quantitatively the effect of cold pool on nocturnal temperature in a closed catchment. In our model, a closed catchment is treated like a "vessel", and a digital elevation model (DEM) was used to calculate the maximum capacity of the cold pool formed in a closed catchment. We introduce a topographical variable named "shape factor", which is the ratio of the cold air accumulation potential across the whole catchment area to the maximum capacity of the cold pool to describe the relative size of temperature drop at a wider range of catchment shapes. The shape factor is then used to simulate the density profile of cold pool formed in a given catchment based on a hypsometric equation. The cold lake module was incorporated with the existing model (i.e., Chung et al., 2006), generating a new model and predicting distribution of minimum temperature over closed catchments. We applied this model to Akyang valley (i.e., a typical closed catchment of 53 $km^2$ area) in the southern skirt of Mt. Jiri National Park where 12 automated weather stations (AWS) are operational. The performance of the model was evaluated based on the feasibility of delineating the temperature pattern accurately at cold pool forming at night. Overall, the model's ability of simulating the spatial pattern of lower temperature were improved especially at the valley bottom, showing a similar pattern of the estimated temperature with that of thermal images obtained across the valley at dawn (0520 to 0600 local standard time) of 17 May 2011. Error in temperature estimation, calculated with the root mean square error using the 10 low-lying AWSs, was substantially decreased from $1.30^{\circ}C$ with the existing model to $0.71^{\circ}C$ with the new model. These results suggest the feasibility of the new method in predicting the site-specific freeze and frost warning at a closed catchment.