• 제어로봇시스템학회논문지
• /
• 제9권1호
• /
• pp.90-98
• /
• 2003

The real-time industrial network, often referred to as fieldbus, is an important element for building automated manufacturing systems. Thus, in order to satisfy the real-time requirements of field devices, numerous fieldbus protocols have been announced. But the application of fieldbus has been limited due to the high cost of hardware and the difficulty in interfacing with multi-vendor products. Therefore, as an alternative to fieldbus, the computer network technology, especially Ethernet (IEEE 802.3), is being adapted to the industrial environment. However, the crucial technical obstacle for Ethernet is its non-deterministic behavior that makes it inadequate for industrial applications where real-time data have to be delivered within a certain time limit. Recently, the development of switched Ethernet shows a very promising prospect for industrial application due to the elimination of uncertainties in the network operation resulting in much improved performance. This paper focuses on the application of the switched Ethernet for industrial communications. More specifically, this paper presents an analytical and experimental performance evaluation of the switched Ethernet and a case study about networked control system.

• 제어로봇시스템학회논문지
• /
• 제10권8호
• /
• pp.718-725
• /
• 2004

The real-time industrial network, often referred to as fieldbus, is an important element for intelligent manufacturing systems. Thus, in order to satisfy the real-time requirements of field devices, numerous fieldbus protocols have been announced. But, the application of fieldbus has been limited due to the high cost of hardware and the difficulty in interfacing with multi-vendor products. Therefore, as an alternative to fieldbus, the computer network technology, especially Ethernet (IEEE 802.3), is being adapted to the industrial environment. However, the crucial technical obstacle for Ethernet is its non-deterministic behavior that makes it inadequate for industrial applications where real-time data have to be delivered within a certain time limit. Recently, the development of switched Ethernet shows a very promising prospect for industrial application due to the elimination of uncertainties in the network operation resulting in much improved performance. This paper focuses on the application of the switched Ethernet with cascade structure for industrial communications. More specifically, this paper presents an analytical performance evaluation of switched Ethernet with cascade structure, and a case study about networked control system.

• 한국방재학회:학술대회논문집
• /
• 한국방재학회 2008년도 정기총회 및 학술발표대회
• /
• pp.417-420
• /
• 2008

Recently, the interest in NDMA(N-nitrosodimethylamine) has increased due to its recognition as a pollutant by Ontario Ministry of Environment and Energy and California Department of Health Sciences. It is, in fact, one of the DBPs(Disinfection By-products) which appears due to chlorination and is reported to be fatal if exposed continuously to human body. Due to uncertainty in mechanism to remove it, its treatment is not yet carried out. In this experiment, treatment of biological NDMA is carried out by letting it adsorbed on Granular Sludge and then filtering the medium through MF(Microfiltration) and UF(Ultrafiltration) membranes. Granular Sludge is adapted to aerobic and anaerobic conditions for 7 days and the experimental conditions are MLSS of 8000mg/L, COD of 250mg/L, TN of 12.5mg/L, and TP of 2.5mg/L. Several batch tests were carried out and samples were collected with the interval of 1 hour. Samples were measured by LSC(Liquid scintillation counter) after filtering by MF and UF. In batch test with granular sludge the permeate concentrations(removal efficiencies) of NDMA by MF and UF were 71.7ng/L(32.0%) and 62.0ng/L(43.7%) at aerobic state, and 52.0ng/L(49.2%) and 47.6ng/L(58.9%) at anaerobic state, respectively. Hence, UF membrane showed about 10% more removal efficiency than MF and removal efficiency at anaerobic condition was 15% more than that at aerobic condition.

• ALGAE
• /
• 제34권1호
• /
• pp.57-70
• /
• 2019

DNA metabarcoding is currently used for large-scale taxonomic identification to understand the community composition in various marine ecosystems. However, before being widely used in this emerging field, this experimental and analytic approach still has several technical challenges to overcome, such as polymerase chain reaction (PCR) bias, and lack of well-established metabarcoding markers, a task which is difficult but not impossible to achieve. In this study, we present an adapted PCR-free small-organelles enriched metagenomics (SoEM) method for marine biodiversity assessment. To avoid PCR bias and random artefacts, we extracted target DNA sequences without PCR amplification from marine environmental samples enriched with small organelles including mitochondria and plastids because their genome sequences provide a valuable source of molecular markers for phylogenetic analysis. To experimentally enrich small organelles, we performed subcellular fractionation using modified differential centrifugation for marine environmental DNA samples. To validate our SoEM method, two marine environmental samples from the coastal waters were tested the taxonomic capturing capacity against that of traditional DNA metabarcoding method. Results showed that, regardless of taxonomic levels, at least 3-fold greater numbers of taxa were identified in our SoEM method, compared to those identified by the conventional multi-locus DNA metabarcoding method. The SoEM method is thus effective and accurate for identifying taxonomic diversity and presents a useful alternative approach for evaluating biodiversity in the marine environment.

• 한국치위생학회지
• /
• 제15권6호
• /
• pp.1033-1041
• /
• 2015

Objectives: The purpose of the study is to find out the effect of part-time employment experience on adaptation to university life in dental hygiene students. Methods: A self-reported questionnaire was completed by 288 dental hygiene students in Seoul and Gyeonggido from September to October, 2014. The questionnaire consisted of general characteristics of the subjects(5 items), part-time employment experience(6 items), and adaptation to university life(53 items). The instrument for adaptation to university life was adapted from Baker and Sirky and modified by Kwon. Likert 5 point scale adaptation included personal emotion adaptation, academic adaptation, social adaptation, and university environment adaptation. Cronbach's ${\alpha}$ was 0.80 in the study. Results: The adaptation to university life was 3.0 points. The higher the economic level was, the higher the personal emotional adaptation(p<0.001) and academic adaptation were(p<0.05). The adaptation to university life was positively influenced by tuition support by parents and part-time employment(p<0.05). The part-time employment was significantly helpful to future job selection, social adaptation, and university environment adaptation(p<0.001). Economic stability and advantage of future job selection had a positive influence on the adaptation to university life. So the adaptation to university life was proportional to younger age, economic stability, and advantage to future job selection. Conclusions: It is very important to give a positive motivation and stimulation, and a careful counseling to the students in part-time employment. In order to encourage the part-time employed students, major-related part-time job opening must be given.

• Safety and Health at Work
• /
• 제3권1호
• /
• pp.71-76
• /
• 2012

Malignant mesothelioma is an uncommon but rapidly fatal disease for which the principal aetiological agent is exposure to asbestos. Mesothelioma is of particular significance in Australia where asbestos use was very widespread from the 1950s until the 1980s. Exposure to asbestos includes occupational exposure associated with working with asbestos or in workplaces where asbestos is used and also 'take-home' exposure of family members of asbestos exposed workers. Asbestos exposure may also be nonoccupational, occurring as a consequence of using asbestos products in non-occupational contexts and passive exposure is also possible, such as exposure to asbestos products in the built environment or proximity to an environmental source of exposure, for example an asbestos production plant. The extremely long latency period for this disease makes exposure assessment problematic in the context of a mesothelioma registry. OccIDEAS, a recently developed online tool for retrospective exposure assessment, has been adapted for use in the Australian Mesothelioma Registry (AMR) to enable systematic retrospective exposure assessment of consenting cases. Twelve occupational questionnaire modules and one non-occupational module have been developed for the AMR, which form the basis of structured interviews using OccIDEAS, which also stores collected data and provides a framework for generating metrics of exposure.

• 전기학회논문지
• /
• 제67권2호
• /
• pp.270-276
• /
• 2018

Apache Spark is one of the high performance in-memory computing frameworks for big-data processing. Recently, to improve the performance, general-purpose computing on graphics processing unit(GPGPU) is adapted to Apache Spark framework. Previous Spark-GPGPU frameworks focus on overcoming the difficulty of an implementation resulting from the difference between the computation environment of GPGPU and Spark framework. In this paper, we propose a Spark framework based on a heterogenous pipeline computing with OpenCL to further improve the performance. The proposed framework overlaps the Java-to-Native memory copies of CPU with CPU-GPU communications(DMA) and GPU kernel computations to hide the CPU idle time. Also, CPU-GPU communication buffers are implemented with switching dual buffers, which reduce the mapped memory region resulting in decreasing memory mapping overhead. Experimental results showed that the proposed Spark framework based on a heterogenous pipeline computing with OpenCL had up to 2.13 times faster than the previous Spark framework using OpenCL.

• 전기학회논문지
• /
• 제58권6호
• /
• pp.1186-1193
• /
• 2009

Wearable ECG monitoring is regarded as one of the most essential part in the ubiquitous healthcare environment and subsequently day-life monitoring of a heart condition has been pursued especially for the elder people. However, there are many problems to accomplish this task such as; i) implementation of long-term monitoring device, ii) development of non-irritating electrode on skin and iii) stable signal acquisition. With these aims, we have focused on implementing a non-irritating electrode with an endurable monitoring device for day-life. To accomplish our tasks, we basically developed four different types of textile electrodes that are adapted by both shape and the composed material; flat or convex shape and Ag-conductive paste material or not. It turns out to be that a convex shape and Ag-paste textile electrode has the best performance in terms of both signal-to-noise ratio (SNR) and Impedance/Phase characteristics. Furthermore, ECG amplifier (35 ${\times}$ 35 mm) has developed to resolve the ECG signal and transfer the signal to desktop computing device or portable one by RF serial communication.

• 한국조경학회지
• /
• 제26권2호
• /
• pp.118-132
• /
• 1998

There are numerous plant and animal species which are adapted to the conditioins of the urban environment. The objectie of landscape and nature conservation in cities can be considered as the perservation of these organisms as the basis for a direct contact between urban dwellers and the landscape elements. However, after 1980 in Korea, green and biotope oases started to develop in the center of the urban area, from which the surrounding population benefited, at least indirectly. Thus urban biotope mapping and biotope informatioin system as a specialized tool of urban ecological landscape planning will make clear the orientation for the preservation of species and renaturalizing measures. The results are as follows : 1) Biotope types in the study area were separated to 21 biotope. 2) The written description of the biotopes took place on the computerized forms. The basis for the uniform inclusion and description of all biotopes surveyed was a codeplan. Additional details were included on the urban biotope mapping. 3) The evaluation of the mapped biotopes was completed to the following aspect, namely " species diversity and biotope conservation value" and "nature experience value". 4) UBM and BIS represent an important basis for decision aid for the city administration within the context of the ecological urban and landscape planning process. 5) The methodology of UBM and BIS in this study area could be extended to whole urban area.to whole urban area.

• 경영과정보연구
• /
• 제23권
• /
• pp.175-199
• /
• 2007

With starting of the WTO system, the environments of international trade and commerce met new aspects of affairs such as lowering of trade barriers among nations and bittering of competition among companies that transcend nation's border. In these changing environments of international trade and commerce, to accomplish high rates of export growth, it is necessary that the government and private companies have to establish new international trade and commerce policies and effective counter plans. In relation to these situations, to cultivate international trade and commerce specialist constantly who can be adapted to the situation of the times, the persons concerned with international trade and commerce education of the university must be considering the change of environments, and analyze the problems and pursue the change constantly to fulfill the needs of the society. Therefore, in this study, we investigated the changing features of the educational environments for international trade and commerce in Korea, and suggested improvement direction of education of international trade and commerce of university. We suggest that following; firstly, development of the link major, secondly, development of standardized curriculum, thirdly, enlargement of cooperation with foreign countrie's universities, and fourthly, activation of the trade incubator project.