• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.3
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• pp.195-202
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• 2007

The normalized difference in incident solar energy between a target surface and a level surface (overheating index, OHI) is useful in eliminating estimation error of site-specific maximum temperature in complex terrain. Due to the complexity in its calculation, however, an empirical proxy variable called northern exposure index (NEI) which combines slope and aspect has been used to estimate OHI based on empirical relationships between the two. An experiment with real-world landscape and temperature data was carried out to evaluate performance of the NEI - derived OHI (N-OHI) in reduction of spatial interpolation error for daily maximum temperature compared with that by the original OHI. We collected daily maximum temperature data from 7 sites in a mountainous watershed with a $149 km^2$ area and a 795m elevation range ($651{\sim}1,445m$) in Pyongchang, Kangwon province. Northern exposure index was calculated for the entire 166,050 grid cells constituting the watershed based on a 30-m digital elevation model. Daily OHI was calculated for the same watershed ana regressed to the variation of NEI. The regression equations were used to estimate N-OHI for 15th of each month. Deviations in daily maximum temperature at 7 sites from those measured at the nearby synoptic station were calculated from June 2006 to February 2007 and regressed to the N-OHI. The same procedure was repeated with the original OHI values. The ratio sum of square errors contributable by the N-OHI were 0.46 (winter), 0.24 (fall), and 0.01 (summer), while those by the original OHI were 0.52, 0.37 and 0.15, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.744-754
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• 2017

In this study, an analytic hierarchy process (AHP) was conducted with the aim of developing a post-disaster refugee housing performance index system (PPS) to improve the post-disaster refugee housing (PRH) performance criteria for the foundation of quality-based development. The PRH was defined as a mid-term temporary housing facility that is used for a certain period before the permanent housing is established. The safety, rapidity, reusability, habitability, and economy were derived from major performance factors through prior research. A hierarchical PPS was organized by linking the major performance factors with the whole life cycle process of PRH. The priority of each performance index of PPS was determined quantitatively using the analytic hierarchy process through an expert survey. Based on AHP analysis, the performance criterion of the total weight 1-10 ranking and the performance criterion of the first rank in each category were classified into the essential performance criterion (must be achieved) and the others were classified into the recommended performance criterion (optional achieved) and the performance index was constructed considering all stages of PRH development. With the completion of the PRH performance index, it is expected that victims will be able to secure stable residence and return to their daily lives quickly.

• Journal of Internet Computing and Services
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• v.12 no.6
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• pp.43-51
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• 2011

The recent development of the technology for wireless mobile computing and applied technology for location-based services has made it possible to support query processing faster than that in the past. However, some technological limitations on hardware and software still exist. The most critical aspects of query processing are accuracy and speed. For improving the accuracy, it is required that detailed information on the data involved in query processing be saved. In this case, the amount of information on the data increases, which decreases the speed. On the other hand, for increasing the speed, it is necessary to reduce the broadcast cycle, which enables rapid data acquisition as desired. In this case, because of insufficient index information, the listen time for the client increases, which may cause unnecessary energy consumption. Therefore, a trade-off occurs between the accuracy and speed. This paper proposes a hierarchical bitmap-based spatial index (HBI) as a solution for the aforementioned problems. HBI describes an object with 0 and 1 on the Hilbert curve map. It reduces the broadcast cycle by decreasing the index size on the basis of bit information and tree structure. Therefore, it is able to shorten the listen time and query processing time. In addition, HBI enables the detection of the locations of all the objects so that it is possible selectively listen to a broadcast. A performance evaluation of the proposed technique demonstrates that it is excellent.

• Korean Journal of Community Nutrition
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• v.23 no.2
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• pp.93-101
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• 2018

Objectives: With the increasing number of single households and so-called Honbab-jok, those who eat alone, people tend to enjoy convenient and simple meals, such as single dish meals. This study was performed to provide data on the energy and nutrient content, and nutritional adequacy of single-dish meal. Methods: From the literature reviews, 61 types of single-dish meals were selected, and divided into 4 groups (steamed rice, noodle, porridge, and sandwich burger), and a further 11 sub-groups (bibimbab, fried rice, topped rice, rolled rice/ warm noodle, cold noodle, seasoned noodle, dukgook/ porridge/, and sandwich, burger). In addition, 382 junior high school students from Gyeonggi, Sejong, Jeonbuk, and Chungnam areas were recruited for the survey. The survey questionnaires were composed of the characteristics, preference, and intake frequency of single-dish meals. The representative energy content (arithmetic mean) of single-dish meals were calculated, and compared with the energy contents of preference and intake frequency-weighted values adjusted. The representative nutrient contents, energy contribution ratio, and INQ (index of nutritional quality) of a single-dish meal were calculated for a nutritional adequacy evaluation. Results: The study subjects considered a single-dish meal as tasty, simple and fast to prepare, inexpensive, nutritious, and no low calorie food. The preference scores of all but 1 sub-group of singledish meals were ${\geq}5.00$ (5.00~5.97), and 1 sub-group (porridge) was 4.67 on a 7-point scale. The intake frequency of 11 sub-groups were 0.31~1.71/week, porridge was the lowest at 0.31 and warm noodles was the highest at 1.71. Fried rice, rolled rice, and warm noodle' intake frequency were ${\geq}1/week$. The representative energy of steamed rice, noodle, sandwich burger were 443, 429, and 428 kcal, respectively, and that of porridge was 264 kcal. Less than 5% differences in the representative energy of 4 groups were observed when adjusted for the preference or intake frequency-weighted values. The energy contribution ratio of macro-nutrients calculations showed that porridge was a high carbohydrate and low fat food, whereas sandwich burger were high fat and low carbohydrate foods. The INQ of calcium and vitamin C were less than 1.0 in all 4 food groups, but the INQ of protein and thiamin were > 1.0 in all 4 single-dish food groups. Conclusions: The representative energy in the 4 groups of single-dish meal was 264~450 kcal, which is a rather low calorie meal, and the energy contribution ratio of macro-nutrients were inadequate. The protein and thiamin levels were sufficient but the calcium and vitamin C levels were insufficient in all 4 groups of a single-dish meal judged by the INQ. The additional intake of fruits and milk dairy products between meals with a single-dish meal, supply of calcium and vitamin C may increase, which will result in an improved nutritional balance.

• Geomechanics and Engineering
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• v.13 no.1
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• pp.63-77
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• 2017

The failure mechanism of a deep hard rock tunnel under high geostress and high geothermalactivity is extremely complex. Uniaxial compression tests of granite at different temperatures were conducted. The complete stress-strain curves, mechanical parameters and macroscopic failure types of the rock were analyzed in detail. The brittleness index, which represents the possibility of a severe brittleness hazard, is proposed in this paperby comparing the peak stress and the expansion stress. The results show that the temperature range from 20 to $60^{\circ}C$ is able to aggravate the brittle failure of hard rock based on the brittleness index. The closure of internal micro cracks by thermal stress can improve the strength of hard rock and the storage capacity of elastic strain energy. The failure mode ofthe samples changes from shear failure to tensile failure as the temperature increases. In conclusion, the brittle failure mechanism of hard rock under the action of thermal coupling is revealed, and the analysis result offers significant guidance for deep buried tunnels at high temperatures and under high geostress.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.158-162
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• 2001

The effects of chemical treatment on Kevlar-29 fibers have been studied in a composite system. The surface characteristics of the Kevlar-29 fibers were characterized by pH, acid-base value and X-ray photoelectron spectroscopy (XPS). The mechanical interfacial properties of final composites were studied by interlaminar shear strength (ILSS) and critical stress intensity factor ($K_{IC}$). Also, the impact properties of the composites were investigated in the differentiating studies between initiation and propagation energies, and ductile index (DI) along with maximum farce and total energy. It was found that the chemical treatment with phosphoric acid ($H_3PO_4$) solution significantly affected the degree of adhesion at interfaces between fibers and resin matrix, resulting in improving the mechanical interfacial strength of the composites. This was probably due to the presence of chemical polar groups on Kevlar surfaces, leading to an increment of interfacial binding force in a composite system.

• Journal of Ocean Engineering and Technology
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• v.25 no.4
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• pp.54-58
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• 2011

The need and importance of developing and utilizing the oceans, not only as sources of renewable energy and mineral resources, but also as countermeasures to global warming such as for CCS (carbon capture and storage), have continued to increase, especially in countries with limited land areas and resources. Therefore, it is necessary to assess the sustainability of an ocean utilization technology or system not only from an economic point of view but also from an ecological one. For this purpose, it might be effective to develop a comprehensive evaluation method and/or index, by which the assessment of and decisions about a technology and system can be made more objectively. It would also be useful to have an environmental simulation model, which was developed and reported in a previous research. The aim of this study was to modify a reasonable and quantitative index, with which a comprehensive evaluation system can be established, to assess environmental sustainability and risk.

• Journal of Environmental Science International
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• v.23 no.5
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• pp.793-800
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• 2014

This study was conducted to observe the influences of Crataegus pinnatifida BUNGE extract on lipid concentration in hypercholesterolemic rats (Sprague Dawley, male) fed the experimental diets for 5 weeks. Body weight gain was remarkably lower in the Crataegus pinnatifida BUNGE extract intake group than in the hypercholesterolemic rats. Total cholesterol concentration was remarkably lower in the extract of Crataegus pinnatifida BUNGE supplement in hypercholesterolemic rats than in the hypercholesterolemic model. Whereas, concentrations of HDL-cholesterol, ratio of HDL-cholesterol concentration to total cholesterol were remarkably higher in the extract of Crataegus pinnatifida BUNGE supplement in hypercholesterolemic rats than in the hypercholesterolemic model. Atherosclerotic index (AI), cardiac risk factor (CRF) were remarkably lower in the extract of Crataegus pinnatifida BUNGE supplement in hypercholesterolemic rats than in the hypercholesterolemic model. From the above research, Crataegus pinnatifida BUNGE extract was effective on the lipid concentrations in sera of dietary hypercholesterolemic rats.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.671-678
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• 2009

This paper presents target operation voltage guidelines of each voltage control area considering both voltage stability and economical efficiency in real power system. EMS(Energy Management System) data, Real-time simulator, shows not only voltage level but lots of information about real power system. Also this paper performs optimal power flow calculation of three objective functions to propose the best target operation voltage. objective function of interchange power flow maximum and active power loss minimization stand for economical efficiency index and reactive power reserve maximum objective unction represents stability index. Then through simulation result using optimazation technique, the most effective objective function is chosen. To sum up, this paper divides voltage control area into twelve considering electric distance characteristics and estimate or voltage level by the passage of time of EMS peak data. And through optimization technique target operation voltage of each voltage control area is estimated and compare heir result. Then it is proposed that the best scenario to keep up voltage stability and maximize economical efficiency in real power system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1257-1264
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• 2018

This paper proposes Autoregressive Integrated Moving Average (ARIMA)-based forecasting algorithms using meteorological indices to predict seasonal peak load. First of all, this paper observes a seasonal pattern of the peak load that appears intensively in winter and summer, and generates ARIMA models to predict the peak load of summer and winter. In addition, this paper also proposes hybrid ARIMA-based models (ARIMA-Hybrid) using a discomfort index and a sensible temperature to enhance the conventional ARIMA model. To verify the proposed algorithm, both ARIMA and ARIMA-Hybrid models are developed based on peak load data obtained from 2006 to 2015 and their forecasting results are compared by using the peak load in 2016. The simulation result indicates that the proposed ARIMA-Hybrid models shows the relatively improved performance than the conventional ARIMA model.