• Korean Journal of Remote Sensing
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• v.35 no.6_4
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• pp.1403-1415
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• 2019

Urban population growth and consequent rapid urbanization involve some thermal environmental problems in the cities. Monitoring of thermal environments in urban areas such as hot spot analysis is required for effective actions to resolve these problems. This study selected 14 dongs and surrounding administrative districts of Sejong city as study areas and analyzed the characteristics of changes in surface temperature due to the urban expansion in the summer from 2013 to 2018. In the study, the surface temperature distributions in the study areas were plotted using surface temperature values from Landsat 8 and NDVI (Normalized Difference Vegetation Index) and NDBI (Normalized Difference Built-up Index) based on KOMPSAT 2/3 data, and the patterns of surface temperature changes with urban expansion were discussed using the estimated NDVI and NDBI. In particular, the distinct urbanization in the study areas were selected for case studies, and the cause of the changes in the hot spots in the regions was analyzed using high-resolution KOMPSAT images. This study results present that hot spots appeared in urbanized regions within the study areas, and it was plotted that the lower the NDVI values and the higher the NDBI values indicate the temperature values are high. The land surface temperature and satellite-based products were used to divide the study areas into continuously urbanized regions and rapidly urbanized regions and to identify the different characteristics depending on land covers. In the regions with distinct surface temperature changes by urbanization, the analysis using high-resolution KOMPSAT images as presented in this study could provide effective information for urban planning and policy utilization in the future.

• Food Engineering Progress
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• v.21 no.4
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• pp.375-382
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• 2017

The purpose of this study was to examine the effect of different types of frying oil on the quality of yakgwa such as expansion rate, color, moisture content and rheological properties. Yakgwa fried with corn oil showed the highest expansion in width and length, and rice bran oil in height. With regard to the overall expansion rate, yakgwa fried with rice bran had the highest value. As for lightness and yellowness, yakgwa fried with soybean oil had the highest lightness (34.74), while yakgwa fried with grape seed oil had the lowest lightness (29.82). As for redness, however, no significant difference was found. Regarding fat content, yakgwa fried with rice bran oil showed the highest value with 18.91%, while yakgwa fried with corn oil and canola oil showed the lowest value. No difference was found in moisture content according to the type of frying oil. In relation to the acid value, yagkwa with soybean oil showed the lowest value of $0.24{\pm}0.66$; as for peroxide value, yagkwa fried with rice bran oil showed the lowest value of $3.59{\pm}1.74meq/kg$. No difference was found in hardness, cohesiveness and resilience according to the type of frying oil. Yagkwa fried with corn oil and canola oil showed the lowest value in terms of adhesiveness and chewiness, respectively. The results of the sensory evaluation showed not significance difference in overall preference, but yakgwa fried with rice bran oil had the highest value of $5.93{\pm}1.87$.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.2955-2960
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• 2012

Product ion yields in the in- and post-source decays of three peptide ions, $[Y_5X+H]^+$ (X = Y (tyrosine), K (lysine), and R (arginine)), generated by matrix-assisted laser desorption ionization (MALDI) were measured at six wavelengths, 307, 317, 327, 337, 347, and 357 nm, using ${\alpha}$-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB) as the matrices. The temperatures of the early and late plumes generated by MALDI were estimated via kinetic analysis of the product ion yield data. For both matrices, the temperature drop (${\Delta}T$), i.e. the difference in the temperature between the early and late plumes, displayed negative correlation with the absorption coefficient. This was in agreement with the previous reasoning that deeper laser penetration and larger amount of material ablation arising from smaller absorption coefficient would result in larger extent of expansion cooling. The results support the postulation of the expansion cooling occurring in the plume presented previously.

• Journal of the Korean Ceramic Society
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• v.31 no.12
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• pp.1521-1528
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• 1994

To improve mechanical strength of bioglass, it is considered to use the glass as a coating material to alumina, but the difference in thermal expansion coefficient between two materials is too high to make a good coating. The aim of the present study, therefore, is to find out proper glass composition matching its thermal expansion coefficient to that of alumina without losing biocompatibility. In the present work, various glasses were prepared by substituting B2O3 and CaO for Na2O in the glass system of 55.1%SiO2-2.6%P2O5-20.1%Na2O-13.3%CaO-8.9%CaF2 (in mole%), and the thermal expansion property and reaction property in tris-buffer solution for the resulting glasses were measured. The thermal expansion coefficient of the glass was decreased with the substitution of B2O3 for Na2O, and it became close to that of alumina in the glass in which 8 mole% of CaO was substituted for Na2O. Hydroxyapatite formation was enhanced and silica rich layer thickness was decreased with B2O3 substitution for Na2O. CaO substitution for Na2O didn't deteriorated the hydroxyapatite development.

• Journal of the Korean Institute of Navigation
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• v.21 no.1
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• pp.33-55
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• 1997

The European expansion in the later middle age, as Adam Smith stated, influenced greatly on development of the world history. In the various events of the European expansion the discovery of the New World by Christopher Columbus is very important because the effect of the discovery of the New World have still continued to the present. I have interested to find out the reason why the western civilization has seized on the hegemony of the world over other civilizations. As many scholars pointed out, the most distinguished difference between the western civilization and other civilizations is that the western civilization was maritime-oriented, while other civilization were continental-oriented. So I set up the maritime histoy on the theme of my study in order to ruminate upon meaning of the se-power that is one of the motivating forces to drive histoy. Maritime history is not simply about that is maritime affairs, but a branch of history that inquires into inter-relations between maritime affairs and inland affairs. Maritime history constitutes of history of naval war, history of shipping and history of marine development. As above reasons, I have interested the European expansion in the later middle age that maritime activity was the most vigorous in the history. This is a case study to compose maritime history.

• Korean Management Science Review
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• v.17 no.1
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• pp.117-134
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• 2000

Pubilc utility industries including the electric utility industry are facing a new stream of privatization com-petition with the private sector and deregulation. The necewssity to solve now and in the future power supply and demand problems has been increasing through the sophisticated generation expansion plan(GEP) approach con-sidering not only KEPCo's supply-side resources but also outside resources such as non-utility generation(NUG) demand-side management (DSM). Under the environmental situation in the current electric utility industry a new approach is needed to acquire multiple resources competitively. This study presents the development of a modified electric generation expansion analysis system(EGEAS) model with avoided cost based on the existing EGEAS model which is a dynamic program to develope an optimal generation expansion plan for the electric utility. We are trying to find optimal GEP in Korea's case using our modified model and observe the difference for the level of reliabilities such as the reserve margin(RM) loss of load probability(LOLP) and expected unserved energy percent(EUEP) between the existing EGEAS model and our model. In addition we are trying to calculate avoided cost for NUG resources which is a criterion to evaluate herem and test possibility of connection calculation of avoided cost with GEP implementation using our modified model. The results of our case study are as follows. First we were able to find that the generation expansion plan and reliability measures were largely influenced by capacity size and loading status of NUG resources, Second we were able to find that avoided cost which are criteria to evaluate NUG resources could be calculated by using our modified EGEAS model with avoided cost. We also note that avoided costs were calculated by our model in connection with generation expansion plans.

• Journal of the Korean Institute of Rural Architecture
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• v.20 no.2
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• pp.11-18
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• 2018

The purpose of this study is to analyze the structure and use change of the private space according to the balcony expansion and use it as the data of plan design. According to Bay, front length/width ratio and the change of balcony space before and after expansion of space organization of house units were analyzed. Common characteristics of Flat type and Tower type are an increase of the frontage length of house units in an apartment, an increase of the number of front bay, and an increase of integrated LDK focusing on living room. A difference is that Flat type shows high frontage ratio, Bay figure, and spatial arrangement favorable to front openness and lighting. Flat type shows higher area distribution than Tower type in LDK area distribution located in at the plane center. Spatial expandability and visual openness of Flat type are more beneficial than those of Tower type in the planning, and a balcony extension of house units has developed to direction to open more. Tower type creates various block images through a combination of house units focusing on the core. Uses after balcony expansion are area expansion of a balcony-neighboring room, storage space, expansion and function improvement of the variable range, and specialized space different from a neighboring room. In addition, there is no escapable space except for a shelter, so unit plan should be prepared to prevent using it other space of a shelter and to solve moving line of two-way horizontal refuge and vertical refuge.

• Journal of the Korean Institute of Rural Architecture
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• v.10 no.2
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• pp.61-70
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• 2008

The purpose of this study is to give some suggestions for the legal supplement of the regulation on the balcony expansion for the optimal use of apartment balcony. For the purpose, this study focused on the characteristics of spaces expanded to the balcony, in the plans supplied after the legalization of balcony expansion, comparing them by their location; the metropolitan area of Seoul Gyeonggi and the districts of the other areas. The 168 plans of apartments in the supplied by top 10 constructors in the metropolitan areas of Seoul and Gyeonggi, together with the 92 plans in the other smaller districts in 2006 to 2007 were analyzed with the tools of frequency and chi-square analysis. The result is as follows. (1) The region showed no difference in the plans of balcony; whereas the size, the position and access of the shelter explained some differences of balcony plan. (2) In wider plans, balconies were placed in all sides of plan-front, rear and side, and were remodeled to expand facing rooms. (3) The balcony expansion tended to increase the number of bays. (4) In almost cases, the living rooms were expanded to balcony. In smaller plans, the balconies were remodeled to supply supplementary kitchen space, splitting it from laundry. (5) The shelters were placed at the rear or side of plans, but the shelter facing room could be dangerous in case of fire. The balcony expansion, despite of legalization spirit to adopt diverse use of additional spaces for residents' needs, was only a tool for the space expansion. The amendment of the regulation is needed to accommodate these findings that the balconies should be identified by their function, that the front corridor-type balcony should be limited in length and magnitude, and that the shelter should be positioned with easy access.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.4
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• pp.135-145
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• 2023

Purpose : The purpose of this study was to discover which breathing technique is more effective in improving respiratory function by applying different breathing techniques-the chest expansion respiratory technique and the abdominal expansion respiratory technique-to adults in the same aerobic exercise situation. Methods : In this study, 30 people were randomly assigned to two groups: chest expansion respiratory technique with aerobic exercise (A group) and abdominal expansion respiratory technique with aerobic exercise (B group). Group A was asked to breathe after wrapping their rib cage with an elastic band, and Group B was asked to breathe after wrapping their abdomen with an elastic band. A total of 3 sets of 30 breaths were performed, 3 times a week for 6 weeks. For statistical processing, an independent t-test was used to verify homogeneity between the two groups, and a repeated measure analysis of variance (ANOVA) was used to compare differences according to the period for each group. Results : The changes in FVC and FEV₁ for each group following 6 weeks of intervention are as follows. In comparison according to the intervention period, there was a significant increase in all groups depending on the timing of measurement (p<.05), and as a result of the inter-subject effect test, there was no significant difference between groups (p>.05). In addition, there was no interaction effect between period and group (p>.05). Conclusion : The conclusion of this study is that FVC and FEV₁ values increased according to the intervention period in both groups; therefore, it can be suggested that flexible breathing techniques can be applied depending on the patient's physical situation when applying a breathing program to improve respiratory function.

• Journal of applied mathematics & informatics
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• v.39 no.5_6
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• pp.655-676
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• 2021

A parameter uniform numerical scheme is proposed for solving singularly perturbed parabolic partial differential-difference convection-diffusion equations with a small delay and advance parameters in reaction terms and spatial variable. Taylor's series expansion is applied to approximate problems with the delay and advance terms. The resulting singularly perturbed parabolic convection-diffusion equation is solved by utilizing the implicit Euler method for the temporal discretization and finite difference method for the spatial discretization on a uniform mesh. The proposed numerical scheme is shown to be an ε-uniformly convergent accurate of the first order in time and second-order in space directions. The efficiency of the scheme is proved by some numerical experiments and by comparing the results with other results. It has been found that the proposed numerical scheme gives a more accurate approximate solution than some available numerical methods in the literature.