• Journal of the Korean Geotechnical Society
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• v.21 no.6
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• pp.41-52
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• 2005

Because the allowable current loading of buried electrical transmission cables is frequently limited by the maximum permissible temperature of the cable or of the surrounding ground, there is a need fur cable backfill materials that can maintain a low thermal resistivity even while subjected to high temperatures for prolonged periods. Temperatures greater than $50^{\circ}C\;to\;60^{\circ}C$ may lead to breakdown of cable insulation and thermal runaway if the surrounding backfill material is unable to dissipate the heat as rapidly as it is generated. This paper describes the results of studies aimed at the development of backfill material to reduce the thermal resistivity. A large number of different additive materials were tested to determine their applicability as a substitute material. Tests were carried out for Dongrim river sand, a relatively uniform sand of very high thermal resistivity, $50^{\circ}C-cm/watt\;at\;10\%$ water content, $260^{\circ}C-cnuwatt$ when dry, and Jinsan granite screenings, and D-2 (sand and granite screenings mixture), E-1 (rubble and granite screenings mixture), a well-graded materials with low thermal resistivity, about $35^{\circ}C-cm/watt$ when at 10 percent water content, $100^{\circ}C-cm/watt$ when dry. Based on this research, 3 types of backfill materials were suggested for improved materials with low thermal resistivity and the applicability was assessed through field tests.

• Journal of Korean Home Economics Education Association
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• v.17 no.4 s.38
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• pp.1-26
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• 2005

The Purpose of this study was to investigate the eating habits, nutrition and dietary fiber intakes of middle school students from urban areas, Jinju city and rural areas, Hadong and Namhae Gun in Gyeongnam province. Data were collected by using a survey questionnaire. The result of this study are as follows: In the respects of eating habits, the eating habits of girl students ware worse than those of boy students Regardless of region and subjects, the intakes of energy, calcium, iron, riboflavin, dietary fiber were poor. In all the regions the intakes of dietary fiber was far less than $20\~25g$ of daily intakes level. Mental education should also be emphasized to form teenagers' self-identity and the sense of value. Also, the nutritionists of each school should try to focus on the composition of group meals containing fish, vegetables, Kimchi and boiled rice and cereals, not satisfying with the group meals centered on hygiene. Health and nutrition depends on the food people take, teenagers' health is the basis of their future health. The continuous study about teenagers' eating habits and dietary fiber needs to be emphasized.

• Korean Journal of Community Nutrition
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• v.11 no.4
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• pp.512-519
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• 2006

The purpose of this study was to analyze the influence of the consumer-brand relationship quality on the customer satisfaction in the family restaurant. The questionnaires were distributed to 320 students in the K University located in Masan, who were sampled by convenience-sampling method. The surveys were conducted from November 10 to 24, 2005. The 287 questionnaires responded, and 15 unusable questionnaires were excluded, then 272 were used for the final analysis (response rate: 85.0%). For the statistical analysis, SPSS (12.0) was used to conduct the descriptive analysis, factor analysis, reliability analysis, Pearson correlation and multiple regression analysis. The result of this study showed that 2 constructs (trust and intimacy) of consumer-brand relationship quality have significant positive effects on the customer satisfaction in the family restaurant (p < .001). It meant that as consumer-brand relationship quality becomes stronger, the customer satisfaction becomes greater. As a conclusion, the foodservice manager in the family restaurant should focus on the marketing strategy to strengthen the quality of consumer-brand relationship in order to increase the satisfaction of customers.

• The KIPS Transactions:PartD
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• v.10D no.7
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• pp.1067-1076
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• 2003

Database sharing system (DSS) refers to a system for high performance transaction processing. In DSS, the processing nodes are locally coupled via a high speed network and share a common database at the disk level. Each node has a local memory and a separate copy of operating system. To reduce the number of disk accesses, the node caches database pages in its local memory buffer. In this paper, we propose a dynamic transaction routing algorithm to balance the load of each node in the DSS. The proposed algorithm is novel in the sense that it can support node-specific locality of reference by utilizing the primary copy authority assigned to each node; hence, it can achieve better cache hit ratios and thus fewer disk I/Os. Furthermore, the proposed algorithm avoids a specific node being overloaded by considering the current workload of each node. To evaluate the performance of the proposed algorithm, we develop a simulation model of the DSS, and then analyze the simulation results. The results show that the proposed algorithm outperforms the existing algorithms in the transaction processing rate. Especially the proposed algorithm shows better performance when the number of concurrently executed transactions is high and the data page access patterns of the transactions are not equally distributed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.634-642
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• 2020

With the proliferation of Internet of Things (IoT) devices, using the Linux operating system in various architectures has increased. Also, security threats against Linux-based IoT devices are increasing, and malware variants based on existing malware are constantly appearing. In this paper, we propose a system where the binary data of a visualized Executable and Linkable Format (ELF) file is applied to Local Binary Pattern (LBP) image processing techniques and a median filter to classify malware in a Convolutional Neural Network (CNN). As a result, the original image showed the highest accuracy and F1-score at 98.77%, and reproducibility also showed the highest score at 98.55%. For the median filter, the highest precision was 99.19%, and the lowest false positive rate was 0.008%. Using the LBP technique confirmed that the overall result was lower than putting the original ELF file through the median filter. When the results of putting the original file through image processing techniques were classified by majority, it was confirmed that the accuracy, precision, F1-score, and false positive rate were better than putting the original file through the median filter. In the future, the proposed system will be used to classify malware families or add other image processing techniques to improve the accuracy of majority vote classification. Or maybe we mean "the use of Linux O/S distributions for various architectures has increased" instead? If not, please rephrase as intended.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.11
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• pp.527-536
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• 2017

With the recent development of smart grid industry, the necessity for efficient EMS(Energy Management System) has been increased. In particular, in order to reduce electric load and energy cost, sophisticated electric load forecasting and efficient smart grid operation strategy are required. In this paper, for more accurate electric load forecasting, we extend the data collected at demand time into high time resolution and construct an artificial neural network-based forecasting model appropriate for the high time resolution data. Furthermore, to improve the accuracy of electric load forecasting, time series data of sequence form are transformed into continuous data of two-dimensional space to solve that problem that machine learning methods cannot reflect the periodicity of time series data. In addition, to consider external factors such as temperature and humidity in accordance with the time resolution, we estimate their value at the time resolution using linear interpolation method. Finally, we apply the PCA(Principal Component Analysis) algorithm to the feature vector composed of external factors to remove data which have little correlation with the power data. Finally, we perform the evaluation of our model through 5-fold cross-validation. The results show that forecasting based on higher time resolution improve the accuracy and the best error rate of 3.71% was achieved at the 3-min resolution.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.4
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• pp.489-495
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• 2005

The purpose of this study was to analyze the effect of the consumer-brand relationship Quality (CBRQ) on the brand loyalty in the fast food restaurant in Masan, Korea. The Questionnaires were distributed to 250 students in the K University located in Masan, who were sampled by convenience-sampling method. The surveys were performed from December 6 to 14, 2004. The 246 Questionnaires were responded, and 12 unusable Questionnaires were excluded, then 234 were used for the final analysis $(response rate:\;93.7\%)$. For the statistical analysis, SPSS (12.0) was used to conduct the descriptive analysis, factor analysis, reliability analysis, Pearson correlation and multiple regression analysis. The result of this study showed that 2 constructs (satisfaction and commitment) of consumer-brand relationship Quality have significant positive effects on the brand loyalty in the fast food restaurant. It meant that as consumer-brand relationship quality becomes stronger, the customer's brand loyalty becomes greater. The differences of customer loyalty between the high and low group of self-connective attachment, satisfaction, commitment, trust and intimacy were significant. So the brand loyalty of high group of customer-brand relationship quality was significantly higher than that of low group of customer-brand relationship quality. As a conclusion, the operator in the fast food restaurant should focus on the marketing strategy to strengthen the quality of consumer-brand relationship in order to increase the brand loyalty of customers.

• Tunnel and Underground Space
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• v.23 no.1
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• pp.1-12
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• 2013

Enhanced oil recovery (EOR) technology coupled with underground carbon dioxide sequestration is introduced. $CO_2$ can be injected into an oil reservoir in order to enhance oil production rate and $CO_2$ EOR can be turned into CCS in a long term sense. Coupling $CO_2$ EOR with CCS may secure a large scale and consistent $CO_2$ source for EOR, and the $CO_2$ EOR can bring an additional economic benefit for CCS, since the benefit from enhanced oil production by $CO_2$ EOR will compensate costs for CCS implementation. In this paper, we introduced the characteristics of $CO_2$ EOR technology and its market prospect, and reviewed the Weyburn $CO_2$ EOR project which is the first large-scale $CO_2$ EOR case utilizing an anthropogenic $CO_2$ source. We also introduced geotechnical elements for a successful and economical implementation of $CO_2$ EOR with CCS and they were a miscroseismic monitoring during and after injection of $CO_2$, and determination of minimum miscible pressure (MMP) and maximum injection pressure (MIP) of $CO_2$.

• Journal of Korean Society of Transportation
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• v.27 no.6
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• pp.79-88
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• 2009

The objective of this study is to develop the new vehicle classification algorithm and minimize classification errors. The existing vehicle classification algorithm collects data from loop and piezo sensors according to the specification("Vehicle classification guide for traffic volume survey" 2006) given by the Ministry of Land, Transport and Maritime Affairs. The new vehicle classification system collects the vehicle length, distance between axles, axle type, wheel-base and tire type to minimize classification error. The main difference of new system is the "Wandering" sensor which is capable of measuring the wheel-base and tire type(single or dual). The wandering sensor obtains the wheel-base and tire type by detecting both left and right tire imprint. Verification tests were completed with the total traffic volume of 762,420 vehicles in a month for the new vehicle classification algorithm. Among them, 47 vehicles(0.006%) were not classified within 12 vehicle types. This results proves very high level of classification accuracy for the new system. Using the new vehicle classification algorithm will improve the accuracy and it can be broadly applicable to the road planning, design, and management. It can also upgrade the level of traffic research for the road and transportation infrastructure.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.317-330
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• 2009

To diminish the levels of organic matters, a novel S-CROM (continuous removal of organic matters in the stream system using freshwater bivalve), was developed and applied to the polluted stream discharging from the wastewater treatment plant, Pocheon stream, Pocheon city (Korea). Major pollutants of the stream were human population and industrial wastewaters. The study was conducted at a small dam constructed within the stream, often called 'bo', and designed with four tanks; no mussels and no sediment (negative control), no mussels and sediment (positive control), 30 mussels and sediment (D1), and 60 mussels and sediment (D2). Physicochemical and biological parameters were measured at 12 hours interval (day and night) after mussel stocking. Results indicated that Anodonta woodiana Lea (D2) clearly removed approximately 72% of chl-$\alpha$ and 57% of suspended solids on second day, however, there were no differences in removal activities between animal densities (P>0.5). Dislike a laboratory CROM system, which previously developed, there were no huge release of nutrient ($NH_3$-N and SRP), due perhaps to the higher flow rate and the lower animal density. Therefore, we may suggest that if we can determine the relevant current and the animal density considering the stream state, an S-CROM system has a strong potential to water quality improvement of eutrophic streams. Some characteristics on both CROM and S-CROM were compared.