• Korean Journal of Cognitive Science
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• v.4 no.2
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• pp.145-180
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• 1994

In this paper,we present an efficient morphological analysis model for Korean which produces from an input word all the feasible sequences of morphemes in the word.This model is deterministic in applying spelling rules,and has few redundant computations in processing complex and ambiguous words.This is the effect of three types of new techniques:first,a new method for interpreting speilling rules;second,predictive rule applications which restrict to the spelling rules suitable for the input word;third,the use of dynamic programming which enables the analyzer to avoid recomputing analyzed substring in case the input word is morphologically ambiguous.our model has been experimented with 413,975 word randomly selected from the corpus of Korean elementary textbooks.Experimental results show that our model guarantees fast and reliable processing.

• The Journal of the Acoustical Society of Korea
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• v.14 no.2
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• pp.30-39
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• 1995

In this paper, study on implementation of FFT analyzer applied to CAT, A/D conversion module, DSP module and VXIbus interface module are implemented in hardware and calculation program and control software are implemented in DSP module and VXIbus interface module, respectively. The control of the modules using PC is realized in software. The real time bandwidth of the FFT analyzing device is 100KHz. At sampling rate of 200KHz and with 2048 point FFT, the result of applying sine, triangular and rectangular wave of 20KHz to FFT analyzing device is compared with the FFT analyzed results of Hewlett-Packard 3562A dynamic output range of -40dBV- +30dBV, correct results are obtained and results of applying 10KHz, 20KHz and 50KHz input are compared and the correct values are obtained.

• ETRI Journal
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• v.39 no.3
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• pp.406-416
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• 2017

Malware propagated via the World Wide Web is one of the most dangerous tools in the realm of cyber-attacks. Its methodologies are effective, relatively easy to use, and are developing constantly in an unexpected manner. As a result, rapidly detecting malware propagation websites from a myriad of webpages is a difficult task. In this paper, we present LoGos, an automated high-interaction dynamic analyzer optimized for a browser-based Windows virtual machine environment. LoGos utilizes Internet Explorer injection and API hooks, and scrutinizes malicious behaviors such as new network connections, unused open ports, registry modifications, and file creation. Based on the obtained results, LoGos can determine the maliciousness level. This model forms a very lightweight system. Thus, it is approximately 10 to 18 times faster than systems proposed in previous work. In addition, it provides high detection rates that are equal to those of state-of-the-art tools. LoGos is a closed tool that can detect an extensive array of malicious webpages. We prove the efficiency and effectiveness of the tool by analyzing almost 0.36 M domains and 3.2 M webpages on a daily basis.

• Journal of KSNVE
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• v.8 no.3
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• pp.494-503
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• 1998

In this paper, in order to analyze dynamic characteristics of an automobile steering system consisting of many components, natural frequencies and transfer functions of each component and the total system are found on a FFT analyzer by experiments. Then, the data are transmitted to a commercial package program, CADA-PC. By analyzing the data, the mode shape of each natural frequency and damping values are obtained. Also, the function of a rubber coupling in column and telescoping effects on system are considered. C.A.E commercial programs are used to compare with the results of experiments. For the finite element modeling, I-DEAS is used. Data processing and post processing are operated on NASTRAN and XL, respectively. The ball-bearing and the linkage of shaft with column are modeled by spring element. Stiffness is modified from the results of experiments. The results of those show close agreement. In the mode shape of total system, wheel mode is dominant at lower frequency, while the column mode is main mode at higher. The role of rubber coupling in vibration isolation is clear on mode shape. Telescoping function makes natural frequency of column changed.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.3
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• pp.40-46
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• 2008

This paper presents the optimal motion control for 3-axis SCARA robot by using $LabVIEW^{(R)}$. Specifically, for optimal motion control of 3-axis SCARA robot, we study velocity profile based on finite jerk(the first derivative of acceleration) and optimal gain tunig based on frequency response method by using $LabVIEW^{(R)}$. The velocity optimization with finite jerk aims at generating the smooth velocity profile of robot. Velocity profile based on finite jerk is acquired and applied to 3-axis SCARA robot by using $LabVIEW^{(R)}$. DSA(Dynamic Signal Analyzer) for frequency response method is programed by using $LabVIEW^{(R)}$. We obtain the bode plot of transfer function about 3-axis SCARA robot by using DSA, and perform the gain tuning considering dynamic characteristic based on the bode plot. These experiments have shown that the proposed motion control can reduce vibration displacement and response error rate each 33.7% and 51.7% of 3-axis SCARA robot.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.64-74
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• 2005

The effect of fuel injection spray on engine performance has been known as one of the major concerns for improving fuel economy and reducing emissions. In general, reducing the spray droplet size could prevent HC emission in gasoline engine. As far as PFI gasoline engine is concerned, the mixture of air and fuel may not be uniform under a certain condition, because breakup and production of spray droplets are made in a short distance between the fuel injector and intake valve. This study, by constituting PFI gasoline spray system, was performed to study the transient spray characteristics and dynamic behavior of droplets from two-holes two-sprays type injector used in DOHC gasoline engine. Mean droplet size and optical concentration in accordance with various conditions were measured by LDPA and CCD camera. Through this study, the variation of drop size and optical concentration could be used for understanding the behavior of unsteady spray was declared and the existing the small droplets between each pulse spray could be estimated caused to the development of wall film was conformed.

• The Research Journal of the Costume Culture
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• v.8 no.5
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• pp.741-753
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• 2000

The purpose of this study : 1. The total 24 range measurements of active dynamic motion of 40 subjects(20's and 30's, and 40's∼60's) using previous studies. The results were compared with the other studies in the aspects of age. In this study, The 3-D motion analysis system consists of VICON 140, data acquisition system, and data analysis program called by KRISSMAS. VICON 140 is dynamic motion analyzer, and KRISSMAS is a program developed for analysis of the data captured from the VICON. The results of this study were as follows : 1. Comparing 20's∼30's and 40's∼60's the result shows that 40's∼60's have smaller ROM at the most joints(Thoratic and Lumber, Hip Joint, Knee Joint, Ankle Joint), which is inconsistent with the previous result. The reason is that most investigations were carried out using traditional measurement equipments, which have encountered difficulty in quantifying the exact motion of the body. 2. There are no significant mean difference between the right and the left side. Most of the significances were not high(〉0.05).

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.641-646
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• 1998

In order to enhance the dynamic and interactive simulation capability of a system thermal hydraulic code for nuclear power plant, applicability of flow network models in SINDA/FLUIN $T^{™}$ has been tested by modeling feedwater system and coupling to DSNP which is one of a system thermal hydraulic simulation code for a pressurized heavy water reactor. The feedwater system is selected since it is one of the most important balance of plant systems with a potential to greatly affect the behavior of nuclear steam supply system. The flow network model of this feedwater system consists of condenser, condensate pumps, low and high pressure heaters, deaerator, feedwater pumps, and control valves. This complicated flow network is modeled and coupled to DSNP and it is tested for several normal and abnormal transient conditions such turbine load maneuvering, turbine trip, and loss of class IV power. The results show reasonable behavior of the coupled code and also gives a good dynamic and interactive simulation capabilities for the several mild transient conditions. It has been found that coupling system thermal hydraulic code with a flow network code is a proper way of upgrading simulation capability of DSNP to mature nuclear plant analyzer (NPA).

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.4
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• pp.403-411
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• 2012

This study presents the nano-sized particle emission characteristics from a small turbocharged common rail diesel engine applicable to prime and auxiliary machines on marine vessels. The experiments were conducted under dynamic engine operating conditions, such as steady-state, cold start, and transient conditions. The particle number and size distributions were analyzed with a high resolution PM analyzer. The diesel oxidation catalyst (DOC) had an insignificant effect on the reduction in particle number, but particle number emissions were drastically reduced by 3 to 4 orders of magnitude downstream of the diesel particulate filter (DPF) at various steady conditions. Under high speed and load conditions, the particle filtering efficiency was decreased by the partial combustion of trapped particles inside the DPF because of the high exhaust temperature caused by the increased particle number concentration. Retarded fuel injection timing and higher EGR rates led to increased particle number emissions. As the temperature inside the DPF increased from $25^{\circ}C$ to $300^{\circ}C$, the peak particle number level was reduced by 70% compared to cold start conditions. High levels of nucleation mode particle generation were found in the deceleration phases during the transient tests.

• Elastomers and Composites
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• v.55 no.3
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• pp.184-190
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• 2020

In the wet master batch process, process oil is used to improve the workability of silica-SBR. The process oil expands the polymer and provides lubrication to soften the stiff rubber chain. However, addition of excess process oil can interfere in the crosslinking reaction between rubber molecules and reduce the crosslinking density of silica-SBR. Controlling the amount of process oil is an important aspect for properly controlling the workability and crosslinking density of silica-SBR. In this study, silica-SBR was prepared by adjusting the amount of process oil to confirm its effect on silicaSBR. Vulcanization characteristics of silica-SBR were examined using a moving die rheometer. Dynamic viscoelasticity was measured using a dynamic mechanical thermal analyzer, and the mechanical properties were investigated using the universal testing machine according to ASTM D412. As a result, all silica-SBR compounds with 10 to 40 phr of process oil have effects of improving the processability and the silica dispersibility. Also, the optimum condition was determined when 10 phr of processed oil was added because the abrasion resistance was improved 65% compared to that at 40 phr.