• The KIPS Transactions:PartA
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• v.16A no.6
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• pp.481-488
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• 2009

GIS is used to isolate large power electrical equipment using SF6 gas. While GIS has simple structure, it has few break down, relatively high reliability. But it is hard to check up faults for reason of pressure. Faults of GIS should have a ripple effect on community and be hard to recovery. Consequently, GIS imports a preventive diagnostic system to find internal faults in advance. It is most important that reliability on the GIS preventive diagnostic system, because it estimates abnormality of system by analysis result of collected data. But, exist system which used central data management is low efficiency, and hard to guarantee timeliness and accuracy of data. To guarantee timeliness and accuracy, the GIS preventive diagnostic system needs accordingly to use a real-time middleware. So, in this paper, to improve reliability of the GIS preventive diagnostic system, we use a middleware based on TMO for guaranteeing timeliness of real-time distributed computing. And we propose an improved GIS preventive diagnostic system applying data acquisition, monitoring and control methods based on the TMO model. The presented system uses the Communication Control Unit(CCU) for distributed data handling which is supported by TMO. CCU can improve performance of the GIS preventive diagnostic system by guaranteeing timeliness of data handling process and increasing reliability of data through the TMO middleware. And, it has designed to take full charge of overload on a data acquisition task had been processed in an exist server. So, it could reduce overload of the server and apply distribution environment from now. Therefore, the proposed system can improve performance and reliability of the GIS preventive diagnostic system and contribute to stable operation of GIS.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.3
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• pp.162-175
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• 2018

The purpose of this study was to analyze the surface temperature of surface fabrics using UAV TIR images, to mitigate problems in the thermal environment of urban areas. Surface temperature values derived from UAV images were compared with those measured in-situ during the similar period as when the images were taken. The difference in the in-situ measured and UAV image derived surface temperatures is the highest for gray colored concrete roof fabrics, at $17^{\circ}C$, and urethane fabrics show the lowest difference, at $0.3^{\circ}C$. The experiment power of the scatter plot of in-situ measured and UAV image derived surface temperatures was 63.75%, indicating that the correlation between the two is high. The surface fabrics with high temperature are metal roofs($48.9^{\circ}C$), urethane($43.4^{\circ}C$), and gray colored concrete roofs($42.9^{\circ}C$), and those with low temperature are barren land($30.2^{\circ}C$), area with trees and lawns($30.2^{\circ}C$), and white colored concrete roofs($34.9^{\circ}C$). These results show that accurate analysis of the thermal characteristics of surface fabrics is possible using UAV images. In future, it will be necessary to increase the usability of UAV images via comparison with in-situ data and linkage to satellite imagery.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.315-327
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• 2017

This study was carried out to examine the converging factors related to academic burnout in students from health-related majors who are involved in studying for the Test of English for International Communication (TOEIC). Research subjects included 291 randomly selected students from the J-region, who were enrolled in TOEIC classes. Data collection took place from April 3, 2017 to April 14, 2017, using anonymous self-administered questionnaires. The results of a multiple regression analysis in female students showed higher academic burnout pertaining to studying for the TOEIC when sleeping hours, self-worth, self-efficacy, school adaptation resilience, and study immersion were low, and job-seeking stress and test anxiety were high. The explanatory power of this model was 65%. Based on these results, to reduce academic burnout pertaining to studying for the TOEIC in health majors, it is first necessary to increase sleeping hours, self-worth, self-efficacy, school adaptation resilience, and study immersion, and to make efforts to manage self-competence, job-seeking stress, and test anxiety. The results of this study may be used to decrease the academic burnout caused by studying for the TOEIC in health major students and to increase their aptitude for studying English, to cultivate globalized capabilities. Future studies need to conduct an effect analysis on the control and mediation effect that these factors have on academic burnout.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.3
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• pp.78-87
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• 2013

NAND flash memory has been widely used as a storage medium in mobile devices, PCs, and workstations due to its advantages such as low power consumption, high performance, and random accessability compared to a hard disk drive. However, NAND flash cannot support in-place update so that it is mandatory to erase the entire block before overwriting the corresponding page. In order to overcome this drawback, flash storages need a software support, named Flash Translation Layer. However, as the high performance mass NAND flash memory is getting widely used, the size of mapping tables is increasing more than the limited DRAM size. In this paper, we propose an adaptive mapping information caching algorithm based on page mapping to solve this DRAM space shortage problem. Our algorithm uses a mapping information caching scheme which minimize the flash memory access frequency based on the analysis of several workloads. The experimental results show that the proposed algorithm can increase the performance by up to 70% comparing with the previous mapping information caching algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.326-332
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• 2018

Korea faces major changes in energy policy, which include eco-friendly and zero-nuclear power. On the other hand, there are very few policies for the waste-management of mid- to large-sized lithium-ion batteries, such as electric car batteries and energy storage systems, which are expected to increase explosively due to such energy policy changes. Therefore, this study estimated the amount of mid- to large-sized lithium ion batteries waste and performed economics analysis of a middle and large sized secondary battery recycling project. Based on the results, a policy alternative for the revitalization of the related lithium-ion battery recycling industry is suggested. As a result, the B / C ratio of a domestic mid - to large - sized lithium ion battery recycling project is 1.06, in which the benefit is higher than the cost, so the business is economic feasible. Although the recycling project's economic efficiency is high, the recycling industry has not been activated in Korea because the domestic demand for rechargeable batteries recycling is very low. To solve this problem, this study proposes a plan to activate the industry by adding lithium secondary batteries to the EPR (Extended Producer Responsibility) items.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.9
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• pp.615-625
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• 2006

Nonvolatile memory technology is evolving continuously and commercial products such as FeRAM and PRAM are now challenging their markets. As NVRAM has properties of both memory and storage, it can store persistent data objects while allowing fast and random access. To utilize NVRAM for general purpose storing of frequently updated data across power disruptions, some essential features of the file system including naming, recovery, and space management are required while exploiting memory-like properties of NVRAM. Conventional file systems, including even recently developed NVRAM file systems, show very low space efficiency wasting more than 50% of the total space in some cases. To efficiently utilize the relatively expensive NVRAM, we design and implement a new extent-based space-thrifty file system, which we call NEBFS (NVRAM Extent-Based File System). We analyze and compare the space utilization of conventional file systems with NEBFS and validate the results with experimental results observed from running the file system implementations on a system with actual NVRAM installed as well as on systems emulating NVRAM. We show that NEBFS has high space efficiency compared to conventional file systems.

• Korean Journal of Remote Sensing
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• v.32 no.6
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• pp.579-587
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• 2016

To obtain a stable energy supply and manage PhotoVoltaic (PV) systems efficiently, satellite imagery methods are being developed to estimate the solar PV potential. This study analyzed trends in the use of satellite imagery in solar PV and solar irradiation estimation technology. The imaging technology is used to produce solar energy resource maps. The trend analysis showed that the level of solar PV technology in Korea is 30% below that of advanced countries. It is impossible to raise such low-level technologies to the levels of advanced countries quickly. Intensive research and development is the only way to achieve the 80% technology level of advanced countries. The information produced in this process can contribute to the management of solar power plants. A valid technology development strategy would be to obtain effective data that can be used for fieldwork. Such data can be produced by estimating solar irradiation very accurately with several-hundred-meter resolution using Communication, Ocean, and Meteorological Satellites (COMS) and next-generation GEO-KOMPSAT 2A, developing core technologies for short- and medium-term irradiation prediction, and developing technologies for estimating the solar PV potential.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.2
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• pp.78-91
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• 2017

In this study, we conducted a comparative study on user's perception and behavior on public system service (PSS) using institutionalism theory and MGA (multi-group analysis) methodology. In particular, this study focuses on how institutional isomorphism is applied to public system services and how MGA can be implemented correctly in a variance based SEM (structural equation model) such as PLS (partial least square). A data set of 496 effective responses was collected from pubic system users and an empirical research was conducted using three segmented models categorized by public proximity theory (public firms = 113, government contractors = 210, private contractors = 173). For rigorous group comparisons, each model was estimated by the same indicators and approaches. PLS-SEM was used in testing research hypotheses, followed by parametric and non-parametric PLS-MGA procedures in testing categorical moderation effects. This study applied novel procedures for testing composite measurement invariance prior to multi-group comparisons. The following main results and implications are drawn : 1) Partial measurement invariance was established. Multi-group analysis can be done by decomposed models although data can not be pooled for one integrated model. 2) Multi-group analysis using various approaches showed that proximity to public sphere moderated some hypothesized paths from quality dimensions to user satisfaction, which means that categorical moderating effects were partially supported. 3) Careful attention should be given to the selection of statistical test methods and the interpretation of the results of multi-group analysis, taking into account the different outcomes of the PLS-MGA test methods and the low statistical power of the moderating effect. It is necessary to use various methods such as comparing the difference in the path coefficient significance and the significance of the path coefficient difference between the groups. 4) Substantial differences in the perceptions and behaviors of PSS users existed according to proximity to public sphere, including the significance of path coefficients, mediation and categorical moderation effects. 5) The paper also provides detailed analysis and implication from a new institutional perspective. This study using a novel and appropriate methodology for performing group comparisons would be useful for researchers interested in comparative studies employing institutionalism theory and PLS-SEM multi-group analysis technique.

• Safety and Health at Work
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• v.11 no.1
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• pp.118-124
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• 2020

Background: The poultry industry in Pakistan has flourished since the 1960s; however, there are scarce data regarding the impact of occupational exposure on the pulmonary health of farm workers in terms of years working in the industry. The objective of the present study was to assess the effect of poultry environment on the health of occupationally exposed poultry farmers in countries of warm climatic regions, such as Pakistan. This study will also show the effect of exposure to poultry facilities on the health of poultry farmers in the context of low-income countries with a relatively inadequate occupational exposure risk management. Materials and methods: The lung function capacity of 79 poultry workers was measured using a spirometer. Along with spirometry, a structured questionnaire was also administrated to obtain information about age, height, weight, smokers/nonsmokers, years of working experience, and pulmonary health of farm workers. The workers who were directly involved in the care and handling of birds in these intensive facilities were considered and divided into four groups based on their years of working experience: Group I (3-10 months), Group II (1-5 years), Group III (6-10 years), and Group IV (more than 11 years). The forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and the FEV1/FVC ratio were considered to identify lung function abnormalities. Statistical analysis was carried out using independent sample t test, Chi-square test, Pearson's correlation, and linear regression. Results: Based on the performed spirometry, 68 (86 %) of workers were found normal and healthy, whereas 11 (14 %) had a mild obstruction. Of the 11 workers with mild obstruction, the highest number with respect to the total was in Group IV (more than 11 years of working experience) followed by Group III and Group II. Most of the workers were found healthy, which seems to be because of the healthy survivor effect. For the independent sample t test, a significant difference was noticed between healthy and nonhealthy farmers, whereas Chi-square test showed a significant association with height, drugs, and working experience. Linear regression that was stratified by respiratory symptoms showed for workers with symptoms, regression models for all spirometric parameters (FVC, FEV1, and FEV1/FVC) have better predictive power or R square value than those of workers without symptoms. Conclusion: These findings suggest that lung function capacity was directly related to years of working experience. With increasing number of working years, symptoms of various respiratory problems enhanced in the poultry workers. It should be noted that most of the poultry workers were healthy and young, the rationale being that there is a high turnover rate in this profession. The mobility in this job and our finding of 86% of the healthy workers in the present study also proposed healthy worker survivor effect.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.73-87
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• 2016

The purpose of this study is to investigate the cultural difference between eastern and western culture in the online community in view of Hofstede dimensions of national culture through social network analysis. And this study tries to interpret the cultural dimensions by using social network indexes. The results show every cultural dimension offered conflicting results except uncertainty avoidance. The eastern culture shows individualism, and low power distance compared to western culture in the online community. Moreover the communication speed of eastern culture is faster than western culture. But eastern culture shows high uncertainty avoidance in the online community similar to an offline culture. This results of this study show that because of certain differences between the offline and online culture, the typical framework we use to analyze offline culture should not be applied to analyze online culture. Therefore we believe that the most important contribution of this study should be related with the finding that we need very different approach to be able to correctly understand the prevalent culture in the online community than the one that we use in the offline community.