• Transactions on Control, Automation and Systems Engineering
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• v.3 no.3
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• pp.146-151
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• 2001

Optical disk drive has excellent advantage of random accessibility of which performance is measured by access time. However, due to the increased rotational velocity of the disk and constraints of mechanical structure, two-stage seek algorithm which executes coarse and fine seeks sequentially has been adopted in most commercial optical disk drives. Although the laser spot is moved to a target track by a single seek operation, the limited operation range of the fine actuator restricts the application of the fine seek algorithm below a few hundreds of tracks. Especially, excessive movement of the objective lens causes a failure in generation of track-cross pulse and results in an unstable seek operation. In this paper, a new control algorithm for extending the fine seek range is proposed with an appropriate control structure. The coarse actuator is utilized to reduce the misalignment between the objective lens and the laser beam axis, and the fine actuator is controlled to follow the reference velocity trajectory. The proposed algorithm is applied to a CD-ROM drive to show its feasibility and some experimental results are presented.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.65-74
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• 2015

X-ray absorption fine structure (XAFS) analysis using X-ray absorption spectroscopy is being applied as a state-of-the-art method in a wide range of disciplines. This review article summarizes the overall procedure of XAFS analysis from the preparation of soil samples to the analysis of data in X-ray absorption near edge structure (XANES) region and extended Xray absorption fine structure (EXAFS) region. The previous studies on application of XANES and EXAFS techniques in environmental soil science field are discussed and classified them according to metal(loid)s (As, Cd, Cu, Ni, Pb, and Zn). A significant number of previous studies of XAFS application in the environmental soil science field have focused on the identification of Pb chemical species in soil. Moreover, XANES and EXAFS techniques have been widely used to investigate the contamination source via identification of metal species. Similarly, these techniques were applied to identify the mechanisms of metal stabilization in soil after application of various amendments, phytoremediation, etc.

• Structural Engineering and Mechanics
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• v.41 no.4
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• pp.559-573
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• 2012

An adaptive modeling and simulation technique is introduced for the effective and reliable fluid-structure interaction analysis using MSC/Dytran for large-scale complex pressurized liquid containment. The proposed method is composed of a series of the global rigid sloshing analysis and the locally detailed fluid-structure analysis. The critical time at which the system exhibits the severe liquid sloshing response is sought through the former analysis, while the fluid-structure interaction in the local region of interest at the critical time is analyzed by the latter analysis. Differing from the global coarse model, the local fine model considers not only the complex geometry and flexibility of structure but the effect of internal pressure. The locally detailed FSI problem is solved in terms of multi-material volume fractions and the flow and pressure fields obtained by the global analysis at the critical time are specified as the initial conditions. An in-house program for mapping the global analysis results onto the fine-scale local FSI model is developed. The validity and effectiveness of the proposed method are verified through an illustrative numerical experiment.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.6
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• pp.185-192
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• 2022

Multimodal medical image fusion (MMIF) fuses two images containing different structural details generated in two different modes into a comprehensive image with saturated information, which can help doctors improve the accuracy of observation and treatment of patients' diseases. Therefore, a method based on double-layer decomposer and fine structure preservation model is proposed. Firstly, a double-layer decomposer is applied to decompose the source images into the energy layers and structure layers, which can preserve details well. Secondly, The structure layer is processed by combining the structure tensor operator (STO) and max-abs. As for the energy layers, a fine structure preservation model is proposed to guide the fusion, further improving the image quality. Finally, the fused image can be achieved by performing an addition operation between the two sub-fused images formed through the fusion rules. Experiments manifest that our method has excellent performance compared with several typical fusion methods.

• Journal of the Optical Society of Korea
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• v.17 no.2
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• pp.142-147
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• 2013

In order to deduce the difficulty of fixing the Ritchey-Chretien (R-C) dual reflective optical system and enhance the stability of the secondary mirror, a compact integral structure is presented here composed of two transmitting and two reflective aspheric surfaces. The four surfaces were manufactured from a single germanium lens and integrated together. The two reflective surfaces formed by coating the inner reflecting films were assembled in one lens. It makes the installation of the two mirrors easier and the structure of the secondary mirror more stable. A design of mid-wave infrared (MWIR) compact imaging system is presented with a spectral range chosen as $3.7-4.8{\mu}m$. The effective focal length is f=90 mm. The field of view (FOV) for the lens is $4.88^{\circ}$. It has good imaging capability with Modulation Transfer Function (MTF) of all field of view more than 0.55 close to the diffraction limitation. Outdoor experiments were carried out and it is shown that the integral catadioptric optical system performs well on imaging.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.743-747
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• 2005

In South Korea, about 900 metal mines have been abandoned, and about 88 million-t metal mine wastes have been discarded in recent years. The treatment of the tailings which are the main wastes in the abandoned metal mines becomes a social problem because they cause environmental pollution such as acidic waste water generation, groundwater contamination, and dust generation. Since almost whole quantities of the tailings have disposed by landfill now, the development of effective recycling methods for the tailings are strongly requested. It is expected that the fine tailings obtained by centrifugal separation process among the tailings can be utilized as admixture for cement. The purpose of this study is to evaluate the micro-structure of cement mortar admixed with fine tailing. Various admixtures were made of Fine tailings and 2 Types of OPC, fly-ash and blast furnace slag. The hydration reactivity of cement mortar with FT was examined by Porosity, XRD and SEM morphology analysis. The anolytical result about hardened hydrates shows that waste fine tailing help hydrates none densified due to it,s filling-space, These densified effect is concluded with improving the resistance to attack of cement mortar including waste fine tailing.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.549-552
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• 2007

Patterned vertical alignment (PVA) mode requires multi-domain to exhibit wide viewing angle whereas the transmittance is sacrificed. To overcome the demerit, a fine pattern was formed at folded region in PVA Z-shape electrode structure. In the present work fine patterns were formed near domain boundary regions where the unwanted field direction which causes the LC to tilt down in unwanted direction exists. Thereby transmittance is improved near those fine patterns. This method is very simple and more cost-effective process than the other methods. In this article, we show the method of fine pattern formation and its influence on LC molecule in PVA mode with Z-shape electrode structure.

• Speech Sciences
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• v.14 no.4
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• pp.7-24
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• 2007

This paper discusses some current issues regarding how prosodic structure is manifested in fine-grained phonetic details, how prosodically-conditioned articulatory variation is explained in terms of speech dynamics, and how such phonetic manifestation of prosodic structure may be exploited in spoken word recognition. Prosodic structure is phonetically manifested in prosodically important landmark locations such as prosodic domain-final position, domain-initial position and stressed/accented syllables. It will be discussed how each of the prosodic landmarks engenders particular phonetic patterns, ow articulatory variation in such locations are dynamically accounted for, and how prosodically-driven fine-grained phonetic detail is exploited by listeners in speech comprehension.

• 한국해양학회지
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• v.21 no.3
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• pp.184-192
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• 1986

A study on the fine structure of the marine diatom has been carried out for taxonomical purpose during the period from Fib. 1982 to Feb. 1986 in Korean coastal waters. Fine structure of small Thalassiosira (Bacillariophyceae) was studied by means of light and scanning electron microscopy. Firstly, four species of Thalassiosira were identified and described. Of these Thalassiosira weissflogii, T.minima and T.oestrupii var venrickae were new records for Korean coastal waters.

• 한국해양학회지
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• v.22 no.3
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• pp.179-190
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• 1987

A study on the fine structure of the marine diatoms has been carried out for taxonomical purpose during the periods from September 1983 to March 1987 in Korean coastal waters. Fine structure of smallThalassiosira(Bacillariophyceae) was studied by means of light microscope and scanning electron nisroscopy. Secondarily, six species of Thalassiosira were identified and described. Of these Thalassiosia allenii, T. binata and T. conferta were new records for Korean coastal waters. Thalassiosira aestivalis, T.allenii, T.binata, T.conferta, and T. pacifica have a valve with a single labiate process and one central and one marginal ring of strutted processes, but T.rotula has many central strutted processes close together instead of one central strutted process.