• Journal of the Institute of Convergence Signal Processing
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• v.15 no.1
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• pp.15-22
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• 2014

This paper presents the implementation of a control system of pellet boiler using wood pellet as carbon neutral material. The system also has the additional features to provide remote controlling and monitoring based on home networking technology through either public switched telephone networks or mobile communication networks. It consists of three kinds of sub-modules; a main controller provides basic and additional features such as a setting of temperature, a supplying of wood pellet, a controlling of ignition and fire-power, and a removing of soot. The second is temperature controller of individual rooms which is connected to the main controller through RS-485 links. And interface modules with PSTN and mobile networks can support remote controlling and monitoring the functions. The test results under the heating area of $172m^2$ show a thermal efficiency of 93.6%, a heating power of 20,640kcal/hr, and a fuel consumption of 5.54kg/hr. These results are superior to those of the conventional pellet boilers. In order to obtain the such high performance, we newly applied a 3-step ignition flow, a flame detection by $C_dS$ sensor, and a fire-power control by fine controlling of shutter to our pellet boiler.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.504-506
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• 1993

The Joint Photographic Experts Group (JPEG) standard was proposed by the International Standardization Organization (ISO/SC 29/WG 10) and the CCITT SG VIII as an international standard for digital continuous-tone still image compression. The JPEG standard has been widely accepted in electronic imaging, computer graphics, and multi-media applications, however, due to the lossy character of the JPEG compression its application in the field of medical imaging has been limited. In this paper, the JPEG standard was applied to a series of head sections of magnetic resonance (MR) images (256 gray levels, $256{\times}256$ size) and its performance was investigated. For this purpose, DCT-based sequential mode of the JPEG standard was implemented using the CL550 compression chip and progressive and lossless coding was implemented by software without additional hardware. From the experiment, it appears that the compression ratio of about 10 to 20 was obtained for the MR images without noticeable distortion. It is also noted that the error signal between the reconstructed image by the JPEG and the original image was nearly random noise without causing any special-pattern-related artifact. Although the coding efficiency of the progressive and hierarchical coding is identical to that of the sequential coding in compression ratio and SNR, it has useful features In fast search of patient Image from huge image data base and in remote diagnosis through slow public communication channel.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.1
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• pp.56-67
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• 1999

It is desired to use a domestically manufactured ocean data buoy for the long-term operational ocean monitoring. The ocean data buoy manufacturing technology was introduced through the research cooperation with the Qingkong University of Taiwan. The introduced ocean data buoy system was further expanded and improved for more efficient application for the marine environmental monitoring in Korea. The size of the ocean data buoy is 2.5 m in diameter, which is smaller compared to the NOAA's 3.0 m discus buoy to allow easy land transportation and ocean deployment as well. From the dynamic response test of the buoy carried out numerically, it was shown that the measurement of waves with period greater than 4 seconds is acceptable. The measurement and control system of the data buoy were improved to increase the number of measuring parameters, to reduce power consumption and to enhance better data analysis and management. Each component of the improved data buoy system was described in detail in this paper. Water quality sensors of water temperature, salinity, DO, pH and turbidity were added to the system in addition to the marine meteorological sensors of wind speed and direction, air temperature, humidity, air pressure and wave. Inmarsat satellite communication system is used for the real-time data telemetry from the buoy deployed offshore. A field performance test of the improved and domestically manufactured buoy was carried out for a month at the open sea off Pohang together with DatawelI's Wave-rider buoy to compare the wave data. The results of the test were satisfactory.

• Journal of Korean society of Dental Hygiene
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• v.15 no.2
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• pp.343-352
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• 2015

Objectives: The purpose of this study was to compare the liberal arts curricula of domestic 3 year and 4 year dental hygiene departments and to obtain the basic data for the development of a standardized dental hygiene curriculum. Methods: The liberal arts curricula of fifteen 3 year and 4 year dental hygiene departments in Korea and other countries were analyzed. A survey was conducted on 801 selected dental hygiene majors from December 8 to 12, 2014. A self-reported questionnaire was completed by 750 dental hygiene students and 150 dental hygiene professors. The questionnaire consisted of 5 questions of general characteristics and 13 questions including curricula change, usability of curricula, awareness of the suitability of dental hygiene curricula, and validity of curricula. Cronbach'a alpha was 0.71 in this study. Results: The grade point average in the liberal arts courses in Korean 4 year dental hygiene departments were 29, which was higher than that in 3 year dental hygiene departments of 13.2. There were large disparities among the colleges in the credits of these courses. The most common liberal arts courses in 4 year dental hygiene departments were foreign languages, man, society and communication, and natural science. In 3 year dental hygiene departments, English and foreign languages were the most common courses, followed by computer, man and society, philosophy and ethics. Foreign languages were considered to be the liberal arts course that should be most strengthened according to the job environment change of dental hygienist in globalizing society, followed by social psychology and pedagogy. Conclusions: Liberal arts courses were offered in the 4 year dental hygiene departments than in the 3 year dental hygiene departments in Korea, but there were a great deal of differences between colleges. The preparation of standardized guidelines on liberal arts courses are necessary. Liberal arts courses should support the performance skill and knowledge of the dental hygienists.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.705-716
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• 2020

This triangulation study was performed in order to analyze the team competency effect of a capstone design nursing research course, and to appraise the content of team activity experiences. Subjects were 99 nursing students who were educated in the capstone design nursing research at D university. The teamwork competency of nursing students was compared before and after class, and the team activity experiences in the capstone design nursing research class was analyzed through narrative data. Our results show significant increases after class in task performance competency (t=-2.166, p=0.033), which includes goal execution competency (t=-2,224, p=0.028). In the interpersonal competency category, leadership was significantly increased after class (t=-2.085, p=0.040). The 5 categories evaluated were 'difficulties in managing resources', 'aware of the importance of personal effort and competency', 'efforts to effectively distribute roles', 'to realize the importance of communication', and 'strengthen the competency needed for clinical practice'. Through this research, we confirm that the capstone design nursing research course is effective for improving teamwork competency, and it provides a positive team activity experience to nursing students. Taken together, our findings indicate that the capstone design nursing research course can be applied to improve the nursing research competency by strengthening teamwork competency.

• Journal of KIISE:Databases
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• v.31 no.6
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• pp.567-584
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• 2004

As XML becomes popular as the way of presenting information on the web, how to secure XML data becomes an important issue. So far study on XML security has focused on security of data communications by using digital sign or encryption technology. But, it now requires not just to communicate secure XML data on communication but also to manage query process to access XML data since XML data becomes more complicated and bigger. We can manage XML data queries by access control technique. Right now current XML data access control only deals with read operation. This approach has no option to process update XML queries. In this paper, we present XML access control model and technique that can support both read and update operations. In this paper, we will propose the operation for XML document update. Also, We will define action type as a new concept to manage authorization information and process update queries. It results in both minimizing access control steps and reducing memory cost. In addition, we can filter queries that have no access rights at the XML data, which it can reduce unnecessary tasks for processing unauthorized query. As a result of the performance evaluation, we show our access control model is proved to be better than other access control model in update query. But it has a little overhead to decide action type in select query.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5942-5954
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• 2015

IT system in supply chain management(hereafter, SCM) has been regarded as one of competitive advantage to win over competing supply chain. SCM participants rush to adopt IT system to be agile for changing environment. Companies expect the improvement of the process integration over the supply chain, which enhance the overall SCM performance. IT system has been considered to influence on effective communication over the wall of firm boundaries. But, the profitability or the effectiveness of IT investment are controversial. This study try to reemphasize the importance of IT system considering the differences of processes, and the influences on the collaboration of supply chain participants. We want to know the perception level of functional managers for the importances, usages, and contributions of IT system in manufacturing sector. Also, we compare the different perception for collaborative SCM among supplier, buyer, and employees of buyer, and try to understand the context in which the IT investment acceptance occurs. We collected 297 responses(199 from line process and 98 from project process respectively). Results show that the importances, usages, and contributions of IT system are higher in the line process than in the project process.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.11
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• pp.2075-2082
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• 2006

This paper presents modeling and optimization techniques for hish efficiency solar cell process on single-crystalline float zone (FZ) wafers. Among a sequence of multiple steps of fabrication, the followings are the most sensitive steps for the contact formation: 1) Emitter formation by diffusion; 2) Anti-reflection-coating (ARC) with silicon nitride using plasma-enhanced chemical vapor deposition (PECVD); 3) Screen-printing for front and back metalization; and 4) Contact formation by firing. In order to increase the performance of solar cells in terms of efficiency, the contact formation process is modeled and optimized using neural networks and genetic algorithms, respectively. This paper utilizes the design of experiments (DOE) in contact formation to reduce process time and fabrication costs. The experiments were designed by using central composite design which consists of 24 factorial design augmented by 8 axial points with three center points. After contact formation process, the efficiency of the fabricated solar cell is modeled using neural networks. Established efficiency model is then used for the analysis of the process characteristics and process optimization for more efficient solar cell fabrication.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.149-155
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• 2015

This paper proposes 5-MS/s 10-bit digital-to-analog converter(DAC) with the improved linearity. The proposed DAC consists of a 10-bit R-2R-based DAC, an output buffer using a differential voltage amplifier with rail-to-rail input range, and a band-gap reference circuit for the bias voltage. The linearity of the 10-bit R-2R DAC is improved as the resistor of 2R is implemented by including the turn-on resistance of an inverter for a switch. The output voltage range of the DAC is determined to be $2/3{\times}VDD$ from an rail-to-rail output voltage range of the R-2R DAC using a differential voltage amplifier in the output buffer. The proposed DAC is implemented using a 1-poly 8-metal 130nm CMOS process with 1.2-V supply. The measured dynamic performance of the implemented DAC are the ENOB of 9.4 bit, SNDR of 58 dB, and SFDR of 63 dBc. The measured DNL and INL are less than +/-0.35 LSB. The area and power consumption of DAC are $642.9{\times}366.6{\mu}m^2$ and 2.95 mW, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.447-454
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• 2011

Power-line interference(PLI) can distort certain regions in analysing the ECG signal. In particular, the regions such as P and R wave that are important element in diagnosing with arrhythmia is expressed as different type of noise according to the case whether power-line frequency is multiples of sampling frequency and or not. Noise characteristics is also divided into linearity and non-linearity. In this paper, adaptive subtraction method for removing variable PLI of ECG signal is proposed. We classify the multiple relationship between power line and sampling frequency as Multiple and Non-multiple. PLI of Linear segment is extracted through moving average filter, PLI of non-linear segment is extracted through the interference component that is extracted in the linear segment and stored in the temporary buffer. The performance of P wave and R wave detection is evaluated by using 119 data record of MIT-BIH arrhythmia database. The achieved scores indicate P wave detection rate of 97.91%, R wave detection rate of 96.66% and P wave detection rate of 99.01%, R wave detection rate of 97.93% accuracy respectively for Notch filter and proposed subtraction method.