• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.179-184
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• 2005

In the present study, conceptual design of the main wing for 20 seats WIG{wing in Ground Effect) flight vehicle, which will be a high speed maritime transportation system for the next generation, was performed. The high stiffness and strength Carbon-Epoxy material was used for the major structure and the skin-spar with a foam sandwich structural type was adopted for improvement of lightness and structural stability. As a design procedure for this study, firstly the design load was estimated with maximum flight load, and then flanges of the front and the rear spar from major bending load and the skin structure and the webs of the spars were preliminarily sized using the netting rules and the rule of mixture. In order to investigate the structural safety and stability, stress analysis was performed by Finite Element Codes such as NASTRAN/PA TRAN[6] and NISA II [7]. From the stress analysis results, it was confirmed that the upper skin structure between the front spar and rear spar was very unstable for the buckling. Therefore in order to solve this problem, a middle spar and the foam sandwich structure at the upper skin and the web were added. After design modification, even thought the designed wing weight was a little bit heavier than the target wing weight, the structural safety and stability of the final design feature was confirmed. Moreover, in order to fix the wing structure at the fuselage, the insert bolt type structure with six high strength bolts was adopted for easy assembly and removal.

• Journal of Magnetics
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• v.20 no.3
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• pp.229-240
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• 2015

In this study, nanocrystalline ferrite powders with the composition $Ni_{0.5}Zn_{0.5}Fe_2O_4$ were prepared by the autocombustion method. The obtained powders were sintered at $800^{\circ}C$, $900^{\circ}C$ and $1,000^{\circ}C$ for 4 h in air atmosphere. The as-prepared and the sintered powders were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and magnetization studies. An increase in the crystallite size and a slight decrease in the lattice constant with sintering temperature were observed, whereas microstrain was observed to be negative for all the samples. Two significant absorption bands in the wave number range of the $400cm^{-1}$ to $600cm^{-1}$ have been observed in the FT-IR spectra for all samples which is the distinctive feature of the spinel ferrites. The force constants were found to vary with sintering temperature, suggesting a cation redistribution and modification in the unit cell of the spinel. The M-H loops indicate smaller coercivity, which is the typical nature of the soft ferrites. The observed variation in the saturation magnetization and coercivity with sintering temperature has been attributed to the role of surface, inhomogeneous cation distribution, and increase in the crystallite size.

• Journal of fish pathology
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• v.21 no.1
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• pp.67-79
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• 2008

This study was conducted to find out biological response of bivalves exposed to tributyltin chloride(TBTCl). The results of the study confirmed that TBTCl induce the reduction of oxygen consumption rateand histopathological feature in the gill structure of equilateral venus, Gomphina veneriformis. The experi-mental groups consisted of a control and 3 TBTCl exposure groups (0.4, 0.6 and 0.8 yg TBTCl L') and theexperimental period was 36 weeks. For histological analysis, gill tissues were fixed in Bouin's fluid andthen stained H-E stain, AB-PAS (PH 2.5) reaction and Masson's trichrome stain after having serially sec-tioned the tissue by paraffin method at thickness of 4-6 (an. The oxygen consumption rate was not signifi-cantly different between the control and exposure groups at 4 weeks, but in all exposure groups at 28 weeks,it was significantly different to the control. Gill of G. veneriformis had demibranch that attached two sheetsof lamellae and a lamella was composed of numerous filaments, numbering 25 on average. The frontal fila-ment zone had three types of cilia; frontal, latero-frontal and lateral depending on locations while the lateralcilia were the longest and largest in number. The mucous cells observed in filaments were more abundant in(542c) in AB-PAS (PH 2.5) reaction. Gill exposed to TBTCl was extended hemolymph sinus and increased hemocytes at 4 weeks, and then it showed increases of mucous cells and partially disappearance of frontalcilia. In the group of 0.8 yg TBTCl L' at 12 weeks, hypertrophy of frontal and latero-frontal epithelia wasobserved. Also it observed m decrease of mucous cell containing weekly acid mucosubstance and appearedpartially destruction muscle fiber bundle, In the groups of 0.4 and 0.6 ug TBTCl L' at 36 weeks, it appearedpartially modification of epithelia and in 0.8 us TBTCl L' group, observed filaments that come out chiti-nous rod from disappearance of frontal and latero-frontal epithelia.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.2 s.29
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• pp.61-66
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• 2004

By the advent of the high-resolution Satellite imagery, there are increasing needs in image mosaicking technology which can be applied to various application fields such as GIS(Geographic Information system). To mosaic images, various methods such as image matching and histogram modification are needed. In this study, automated image mosaicking is performed using image matching method based on the multi-resolution wavelet analysis(MWA). Specifically, both area based and feature based matching method are embedded in the multi-resolution wavelet analysis to construct seam line.; seam points are extracted then polygon clipping method are applied to define overlapped area of two adjoining images. Before mosaicking, radiometric correction is proceeded by using histogram matching method. As a result, mosaicking area is automatically extracted by using polygon clipping method. Also, seamless image is acquired using multi-resolution wavelet analysis.

• Korean Chemical Engineering Research
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• v.52 no.1
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• pp.26-39
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• 2014

Cu interconnection in electronic devices is fabricated via damascene process including Cu electrodeposition. In this review, Cu electrodeposition and superfilling for fabricating Cu interconnection are introduced. Superfilling results from the influences of organic additives in the electrolyte for Cu electrodeposition, and this is enabled by the local enhancement of Cu electrodeposition at the bottom of filling feature formed on the wafer through manipulating the surface coverage of organic additives. The dimension of metal interconnection has been constantly reduced to increase the integrity of electronic devices, and the width of interconnection reaches the range of few tens of nanometer. This size reduction raises the issues, which are the deterioration of electrical property and the reliability of Cu interconnection, and the difficulty of Cu superfilling. The various researches on the development of organic additives for the modification of Cu microstructure, the application of pulse and pulse-reverse electrodeposition, Cu-based alloy superfilling for improvement of reliability, and the enhancement of superfilling phenomenon to overcome the current problems are addressed in this review.

• Molecules and Cells
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• v.38 no.11
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• pp.925-935
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• 2015

DNA methylation is a well-characterized epigenetic modification that plays central roles in mammalian development, genomic imprinting, X-chromosome inactivation and silencing of retrotransposon elements. Aberrant DNA methylation pattern is a characteristic feature of cancers and associated with abnormal expression of oncogenes, tumor suppressor genes or repair genes. Ten-eleven-translocation (TET) proteins are recently characterized dioxygenases that catalyze progressive oxidation of 5-methylcytosine to produce 5-hydroxymethylcytosine and further oxidized derivatives. These oxidized methylcytosines not only potentiate DNA demethylation but also behave as independent epigenetic modifications per se. The expression or activity of TET proteins and DNA hydroxymethylation are highly dysregulated in a wide range of cancers including hematologic and non-hematologic malignancies, and accumulating evidence points TET proteins as a novel tumor suppressor in cancers. Here we review DNA demethylation-dependent and -independent functions of TET proteins. We also describe diverse TET loss-of-function mutations that are recurrently found in myeloid and lymphoid malignancies and their potential roles in hematopoietic transformation. We discuss consequences of the deficiency of individual Tet genes and potential compensation between different Tet members in mice. Possible mechanisms underlying facilitated oncogenic transformation of TET-deficient hematopoietic cells are also described. Lastly, we address non-mutational mechanisms that lead to suppression or inactivation of TET proteins in cancers. Strategies to restore normal 5mC oxidation status in cancers by targeting TET proteins may provide new avenues to expedite the development of promising anti-cancer agents.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.4
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• pp.379-388
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• 2007

Ever increasing fuel prices and environmental concerns are forcing commercial vessel operators and designers to re-assess current vessel designs with an emphasis on their propulsion systems. The most important parameter determining propulsive efficiency is the diameter of propeller. Many investigations have been carried out to adapt a large and slow turning propeller known as one of the most robust and effective way of achieving high efficiency in ship propulsion system. However, for the same vessel a further increase of propeller diameter would require the modification of the aft end while still paying attention to the hull clearance to prevent excessive propeller excited vibrations. In order to take the advantage of this approach small workboats (e.g. tug boats, fishing vessels etc.) operate in service with a significant increase of aft draught and hence resulting "inclined keel" configuration can be observed. Although it is not unusual to see large vessels sometimes to operate with stern trim to improve their operational performance and fuel efficiency, it is rare to see a such vessel purposely built with an inclined keel feature to fit a large diameter propeller for power saving. This paper investigates the application of the inclined keel configuration to a 3600TEU container vessel with the aim of fitting an 11 % larger diameter propeller (and hence resulting 17.5 % lower rpm) to gain further power saving over the similar size basis container ship with conventional "level keel" configuration.

• Journal of the Korea Society of Computer and Information
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• v.25 no.2
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• pp.133-140
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• 2020

The IISS(Integrated Interface Storage System) software uses communication methods such as DSS(Data Sharing Service), UDP to perform the function of sending all messages from the Combat Management System to the analytical computer. Because IISS software handles all message used in the Combat Management System, the source code is large and has a highly dependent feature on message changes. Modification of software is a task that requires a lot of labor, such as series of software reliability test. so research has been conducted to reduce software development costs, including minimizing software modifications. In this paper, We study the method of messages receiving and architectural structure improvement to minimize reliance on message changes in the Combat Management System and improve the modifiability. Reduced message dependency by changing the way DSS and UDP protocols are communicated to Packet Sniffing. In addition, Factory Method Pattern were applied to improve the software design. Test comparing existing software and development elements have confirmed that the software has improved its modifiability and reuse.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.7
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• pp.1147-1156
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• 2001

In this paper, a new design architecture of radar signal processor in real time is proposed. It has been designed and implemented under the consideration to minimize the inter-processor communication overhead and to maintain the coherence in Doppler pulse domain and in range domain. Its structure can be easily reconfigured and reprogrammed in accordance with an addition of function algorithm or a modification of operational scenario. As we designed a task configuration for parallel processing from measures of computation time for function algorithms and transmission time for results by signal processing, data exchange between processors for performing of function algorithms could be fully removed. Morocco-2 board equipped ADSP-21060 processor of Analog Devices inc. and APEX-3.2 developed for SHARC DSP were used to construct the radar signal processor.

• Journal of the Korean Society for Library and Information Science
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• v.22
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• pp.219-257
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• 1992

Among the Chinese Characters originated in Japan, some of them are very ancient in their origin and others come to exist as different forms by being used widely in forged books in Chinese. These Characters can be divided into three groups. First, the Chinese Characters whose forms are different. Most of these are 'hoiui' (회의)character, being made by imitating the forms of the original Chinese Letters. These characters do have meaning but not pronunciation. This is one distinct feature of Chinese Characters originated in Japan. Second, the Chinese Characters whose meaning has been assigned by the Japanese people. These letters can be grouped into two. One is the letters whose meanings are entirely different from original Chinese Characters, and the other is the letters whose meanings are not known although their pronunciations are known. It can be explained that the letters with different forms are made because of the ignorance of letter's existence. Or, the letters were made on purpose in ordoer to be used in different meanings. Third, the Characters with a partial modification of original Chinese Characters. Among the Characters in three groups above, pure Japanese-made Chinese Characters are those in group one and three since those in group two are Chinese Letters whose meanings (or pronunciation) only are Japanese. As a results of detailed investigation of pure Japanese-made Chinese Character in JIS X 0208-1990, the followings are discovered: 1. Pure Japanese-made Chinese Characters are 147 in numbers. 2. The Characters which were originally Chinese but now considered to be Japanese-made are 5 in numbers. Among these letters, 39 Characters are not listed in TaeHanHwaSaJon(Whose fame is well known as the authoritative dictionary of Chinese Characters), 47 Characters are not found in the dictionaries of Chinese Characters compiled in Korea. 3. 14 Characters seem to be Japanese-made Chinese Characters although it cannot be said so with accuracy because of various meanings found in several dictionaries of Chinese Characrters.