• Journal of Korea Society of Industrial Information Systems
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• v.11 no.4
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• pp.72-81
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• 2006

In this paper, we first define a total of 64 instructions that are considered to be essential and frequently used, construct a datapath diagram, determine the control sequence using a finite state machine, and implement an 8-bit microcontroller using FPGA in VHDL. In the past, only functional simulation results of a rudimentary microcontroller were reported, the microcontroller lacked interrupt handling capability, or it was not implemented in hardware. We have designed a self-contained 8-bit microcontroller such that it can perform data transfer, addition, and logical operations, as well as stack and external interrupt operations. Following timing simulation of the designed microcontroller, we implemented it in an FPGA and verified its operation successfully. The design and implementation has been done under the Altera MAX+PLUS II integrated development environment using the EP1K50TC144-3 chip. The maximum operating frequency, the total number of logic elements used, and the logic utilization were found to be 9.39 MHz, 2813, and 97%, respectively. The result can be used as a microcontroller IP, and as needs arise, the VHDL code can be modified accordingly.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.4
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• pp.171-180
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• 2016

As social networking services such as twitter become increasingly popular, data streams are widely prevalent these days. In order to search data accumulated from data streams efficiently, the use of an index structure is essential. In this paper, we propose an update-efficient, disk-based inverted index structure for efficient keyword search on data streams. When new data arrive at the data stream, the index needs to be updated to incorporate the new data. The traditional inverted index is very inefficient to update in terms of disk I/O, because all index data stored in the disk need to be read and written to the disk each time the index is updated. To solve this problem, we divide the whole inverted index into a sequence of inverted indices with exponentially increasing size. When new data arrives, it is first inserted into the smallest index and, later, the small indices are merged with the larger indices, which leads to a small amortize update cost for each new data. Furthermore, when indices stored in the disk are merged with each other, we minimize the disk I/O cost incurred for the merge operation, resulting in an even smaller update cost. Through various experiments, we compare the update efficiency of the proposed index structure with the previous one, and show the performance advantage of the proposed structure in terms of the update cost.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.5
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• pp.349-357
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• 2003

Several microvascular anastomotic techniques have been described with methodical effectiveness, patency rates, healing state of microscopic findings. This experimental study presents the comparison of three types of arterial microvascular anastomotic techniques: end-to-end(ETE) anastomosis, end-in-end(EIE) anastomosis, and continuous technique. Sixty male Sprague-Dawley rats, 60 femoral arteries were used for this study. Twenty rats per each technique were used and sacrificed at post-operation 1 day, 3 days, a week, 2 weeks for scanning electromicroscopic findings. The patency was monitored by miniDoppler throughout total experimental periods. The anastomotic time on each method was measured to compare the technical effectiveness. The final results were as follows: 1. The anastomotic time for the end-in-end technique was significantly shorter than another techniques. The average time for each technique was measured as 15 minutes on EIE technique, 20 minutes on continuous technique and 25 minutes on ETE technique. 2. The patency rate for the end-in-end technique at 2 weeks also was superior to another techniques. The patency rate for each technique was demonstrated as 90 % on EIE technique, 85 % on ETE technique and 80 % on continuous technique. 3. The scanning electromicroscopic findings on healing condition of vessel endothelium during the observation period showed that the end results of EIE technique, ETE technique and continuous technique in sequence were good. The end-in-end technique proved to be the superior with regard to anastomotic time and patency rate when compared to end-to-end technuqe, so EIE techniqe might be well available for the case of large discrepancy of vessel size. The patency rate, microscopic healing findings in continuous technique were seen as the lowest level among the three anastomotic techniques, therefore the application of continuous technique was recommended only on the inevitable case.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8A
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• pp.820-829
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• 2006

IP-based design methodology has been popularly employed for SoC design to reduce design complexity and to cope with time-to-market pressure. Due to the request for high performance of current mobile systems, embedded SoC design needs a multi-processor to manage problems of high complexity and the data processing such as multimedia, DMB and image processing in real time. Interface module for communication between system buses and processors are required, since many IPs employ different protocols. High performance processors require interface module to minimize the latency of data transmission during read-write operation and to enhance the performance of a top level system. This paper proposes an automatic interface generation system based on FSM generated from the common protocol description sequence of a bus and an IP. The proposed interface does not use a buffer which stores data temporally causing the data transmission latency. Experimental results show that the area of the interface circuits generated by the proposed system is reduced by 48.5% on the average, when comparing to buffer-based interface circuits. Data transmission latency is reduced by 59.1% for single data transfer and by 13.3% for burst mode data transfer. By using the proposed system, it becomes possible to generate a high performance interface circuit automatically.

• Journal of the Korea Convergence Society
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• v.8 no.5
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• pp.79-85
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• 2017

The purpose of this research was to evaluate the clinical and the instrument of convergence utility of transient elastography (FibroScan(R):electromagnetic wave) in diagnosing and treating liver ailments through a comparison and an analysis between liver function blood test and transient elastography (FibroScan(R)) in patients with chronic hepatitis B virus infection. Of all the patients with chronic hepatitis B virus infection who visited clinic B in Daejeon City between July 1, 2015, and February 28, 2016, 75 who underwent a FibroScan(R) test were selected for this study. Their laboratory and liver function test results were compared for a correlation analysis before constructing an ROC (Receiver Operation Characteristic) curve. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were 0.572 and 0.502, respectively, and showed highest correlation with fibrosis score, with statistical significance (p<0.000). Gamma glutamyltranspeptidase, total bilirubin, and alkaline phosphatase levels also showed relatively significant correlations in this order of sequence, while -fetoprotein and total protein levels did not show any statistically significant values. Albumin (-0.449) and platelet levels (-0.373) showed negative correlations with each other and no correlation with fibrosis score (p < 0.000). As liver fibrosis worsened, the accuracy of the ROC curve increased. At the F4 stage, which is the cirrhotic stage, the largest area under the curve was observed. FibroScan(R) showed significant correlation with the ALT (serum glutamic pyruvic transaminase) and AST (serum glutamic oxaloacetic transaminase) levels in the liver function test, which is a routine test for patients with chronic liver ailments. This implies that fibrosis correlates with liver inflammation severity.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.1 s.2
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• pp.41-52
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• 2003

The purpose of this study was to test the effects of the pedestrian green signal adjustment on clearance of the turning vehicles impeding the through traffic flow at the signalized intersections, and thereby, suggest some operational criteria for adjustment of the pedestrian green signal. In order to test such effects, the pedestrian green time was adjusted so that it could started a few seconds later than the vehicle green time during peak hours, and thereby, the turning vehicle volume not cleared at the intersection was measured by extending the time gap by 2 seconds. (In general, the pedestrian green signal turns on at the same time as the vehicle green signal.) The results of this test can be summed up as follows; first, the longer the time gap was, the turning vehicle volume not cleared from the intersection decreased more. Second, in case there existed a storage space between intersection and crosswalk the effect of the turning vehicles on the through traffic flows was minimal. Third, at the pelican, the effect of the turning vehicles on the through traffic flow was minimal due to the structure of the intersection and the phase sequence. In conclusion, it was found that the adjustment of pedestrian green signal had the effect of enhancing the intersection operation. When adjusting the pedestrian green signal, it was deemed necessary to thoroughly survey the geometric structure of the intersection and collect the data on the turning traffic volume and thereby, apply the results of analysis flexibly to each intersection.

• Journal of the Korea Society of Computer and Information
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• v.17 no.5
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• pp.1-7
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• 2012

In this paper, we design and implement the simulator for WAN storage replication model performance evaluation in cloud computing environment. Each cloud of simulator is composed of virtual machine emulator and storage emulator. The virtual machine emulator is composed of read/write ratio module, the read/write sequence combination module, and the read/write request module. The storage emulator is composed of storage management module, data transfer module, read/write operations module, and overhead processing module. Using the simulator, we evaluate performance of migration scheme, pre-copy and the post-copy, considering about read/write ratio, network delay, and network bandwidth. Through simulation, we have confirmed that the average migration time of pre-copy was decreased proportional to the read operation. However, average migration time of post-copy was on the increase. Also, the average migration time of post-copy was increased proportional to the network delay. However, average migration time of pre-copy was shown uniformly. Therefore, we show that pre-copy model more effective to reduce the average migration time than the post-copy model. The average migration time of pre-copy and post-copy were not affected by the change of network bandwidth. Therefore, these results show that selects the storage replication model to be, the network bandwidth know not being the important element.

• The Korean Journal of Mycology
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• v.31 no.2
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• pp.89-93
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• 2003

In order to select suitable bioreactor type inhibiting cell stress during submerged culture of Tricholoma matsutake mycelium, the growth characteristics and ergosterol contents were investigated using the external-loop type of air-lift bioreactor (ETAB), balloon type of air bubble bioreactor (BTBB) and column type of air bubble bioreactor (CTBB). Dry weights of the T. matsutake in the BTBB, ETAB and CTBB were 12 g, 11.4 g, and 9.5 g per 1 litter, respectively. BTBB, ETAB and CTBB reached stagnant phases 16, 20, and 24 days after cultivation, respectively, The BTBB was more suitable for liquid culture of T. matsutake mycelium compared to other bioreactors owing to much mycelia product and short culture period. The ergosterol contents produced by the mycelium in the bioreactors were in sequence of BTBB, CTBB, and ETAB at every growth phase. BTBB might affect the mycelium on producing the smallest size of pellets. BTBB and CTBB got the mycelium precipitated and coagulated under operation of bioreactor sparser, whereas ETAB shown no effect of above phenomenon. A renovated bioreactor combined between a balloon shape of BTBB and an external-loop of ETAB was developed to enhance the efficiency of culture technique.

• 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.

• Informatization Policy
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• v.27 no.3
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• pp.56-81
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• 2020

The purpose of this research is to empirically examine the effects of motivation and skill for digital devices and the Internet on the use of online services in the severely disabled people. In addition to the general effect of digital divide, particularly for the case of severely disabled people, the effects of physical and mental inconvenience of individuals were taken into account and the moderating effect was confirmed by classifying the groups that need help with online activities and those that do not. The 2018 Digital Divide Survey data of the National Information Society Agency was used for the study. As a research method, path analysis and multi-group analysis using a sequence access model to Internet use were performed. As a result, it was confirmed that even in the case of the disabled, the motivational factor affects the skill for digital device operation and Internet use, and this access skill sequentially affects the use of online services. In particular, it was found that the effect of strategic and technical skill for internet use is the most important for the use of online services for the disabled rather than the motivation or a simple operational skill for digital devices. In addition, it was found that even in the disabled group, those requiring help in using the Internet was more passive in using the online service than the rest in the group. The results of this study suggest the need for stronger capacity for physical access as well as support in building strategic and technical skills that enhance responsibilities and protect from risks in using the Internet among the people with disabilities.