• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.6
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• pp.81-88
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• 2022

Titanium alloy (Ti-6Al-4V) has excellent mechanical properties and high specific strength; therefore, it is widely used in aerospace, automobile, defense, engine parts, and bio fields. Particularly in the aerospace field, as it has a low specific gravity and rigidity, it is used for the purpose of increasing energy efficiency through weight reduction of parts, and most have a thin-walled structure. However, it is extremely difficult to machine thin-walled shapes owing to vibration and deformation. In the case of thin-walled structures, the cutting forces and vibrations rapidly increase depending on the cutting conditions, significantly affecting the surface integrity and tool life. In this study, machining experiments on thin-wall milling of a titanium alloy (Ti-6Al-4V) were conducted for each experimental condition with different axial depths of cut, radial depth of cut, and machining sequence. The machining characteristics were analyzed, and an effective machining method was derived by a comprehensive analysis of the machined surface conditions and cutting signals.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1626-1633
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• 2021

In an industrial field, non-destructive testing (NDT) is commonly used to inspect industrial products. Among NDT methods using radiation sources, X-ray laminography has several advantages, such as high depth resolution and low computational costs. Moreover, an X-ray laminography system with stationary source array and compact detector is able to reduce mechanical motion artifacts and improve inspection efficiency. However, this system, called stationary inverse-geometry X-ray laminography (s-IGXL), causes truncation artifacts in reconstructed images due to limited fields-of-view (FOVs). In this study, we proposed a projection data correction (PDC) method to reduce the truncation artifacts arisen in s-IGXL images, and the performance of the proposed method was evaluated with the different number of focal spots in terms of quantitative accuracy. Comparing with conventional techniques, the PDC method showed superior performance in reducing truncation artifacts and improved the quantitative accuracy of s-IGXL images for all the number of focal spots. In conclusion, the PDC method can improve the accuracy of s-IGXL images and allow precise NDT measurements.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.33 no.2
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• pp.64-76
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• 2022

Praat is a useful analysis tool for linguists, engineers, doctors, speech-language pathologits, music majors, and natural scientists. Basic parameters including duration, pitch, energy and perturbation parameters such as jitter and shimmer can be easily measured and manipulated in the sound editor. When a more in-depth analysis is needed, it is recommended to understand the advanced menus of the object window and learn how to use them. Among the object window menus, vowel formant analysis, spectrum analysis, and cepstrum analysis can be cited as useful ones in the clinical field. The spectrum object can be usefully used for voice quality measurement and diagnosis of patients with voice disorders by showing the energy distribution according to frequency axis (domain). A cepstrum object is useful for speech analysis when periodicity of the sound object is not measurable. The low to high ratio obtained from the spectral object and the CPPs measured from the cepstrum object have attracted many researchers, and it has been proven that the CPPs measured in Praat are relatively excellent.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.347-351
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• 2010

In this paper, our effort to apply 3-D Virtual Reality system for stereoscopic visualization of flow data is briefly described. This study is an extension of our previous and on-going research efforts to develop DATA(Data Analysis and Visualization Application) program, which is a data visualization program developed by using Qt as GUI development environment and OpenGL as graphic library. The program is developed upon the framework of object-oriented programming and it was originally developed by using Qt 3.3.3 environment. In this research the program is converted into a Qt 4.3.3-compatible version, and this new version is developed on Visual Studio 2005. And to achieve a stereoscopic viewing capability, two graphic windows are used to render its own viewing image for the lift and right eye respectively. These two windows are merged into one image using 3D monitor and the viewers can see the data visualization results with stereoscopic depth effects by using polarizing glasses. In this paper three dimensional data visualization with stereoscopic technique combined with 3D Monitor is demonstrated, and the current achievement would be a good start-up for further development of low-cost high-quality stereoscopic data visualization system.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.631-636
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• 2009

Foreground segmentation methods have steadily been researched in the field of computer vision. Especially, background subtraction which extracts a foreground image from the difference between the current frame and a reference image, called as "background image" have been widely used for a variety of real-time applications because of low computation and high-quality. However, if the background scene was dynamically changed, the background subtraction causes lots of errors. In this paper, we propose an efficient background subtraction method in dynamic environment with both static and dynamic scene. The proposed method is a hybrid method that uses the conventional background subtraction for static scene and depth information for dynamic scene. Its validity and efficiency are verified by demonstration in dynamic environment, where a video projector projects various images in the background.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.278-278
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• 2022

Recently, the yield potential of high yield Tongil-type rice varieties has greatly increased, reaching 817kg/10a(Geumgang No.1). Moreover, in order to promote rice consumption and strengthen the competitiveness of the rice processing industry, the R&D of high yield Tongil-type rice varieties for each processing purpose, such as rice noodles, grain feed and industrial materials, has been continuously carried out. However, because Tongil-type rice varieties or lines are generally very vulnerable to cold damage, cold tolerance test can be said to be absolutely necessary to improve the cultivation safety. This study is the result of the seedling and field cold tolerance characteristic tests carried out in 2021 of high yield Tongil-type rice breeding lines. For the cold tolerance characteristic test of seedlings, total 303 high yield rice breeding lines for processing were treated in cold water of 13℃ and irrigation depth of 4cm for 10 days from the third-leaf age, then it was evaluated by comparing the degree of discoloration and withering with the checked varieties(Boramchan, Hanahreum No.2). Also, for the test of field, total 186 high yield rice breeding lines for processing were treated in cold water of 17℃ by keeping pouring day and night from 30 days after transplanting to ripening stage, then it was evaluated by comparing the degree of discoloration, delay of heading, shortening rate of stem length and percent of fertile grain etc. with the checked varieties. And the cold tolerance evaluative criteria were classified as strong(1~3), medium(4~6) and weak(7~9) in overall cold tolerance. (Seedling test) As for the degree of cold tolerance of the check variety, 'Boramchan' and 'Hanahreum No.2' showed a response of 'medium' and 'weak', respectively. However, there was no 'strong' line in the high yield rice breeding lines, 2 lines showed a 'medium' response, and 301 lines showed a 'weak' response. Therefore, except for a few lines(0.7%), most lines(99.3%) showed a 'weak' response. (Field test) In terms of the overall cold tolerance of the check variety, both 'Boramchan' and 'Hanahreum No.2' showed a 'medium' response. Similarly, there was no 'strong' line in the case of high yield rice breeding lines, 20 lines showed a 'medium' response, and 166 lines showed a 'weak' response. Therefore, except for some(10.8%) lines, most(89.2%) lines showed a 'weak' response. From the above results, we selected about 100 individuals with less seed shattering and degeneration of the ear tip, and with a relatively high percent of fertile grain, and are continuing to select lines with improved cold tolerance in the F4~F5 group in this year. As such, most of the Tongil-type rice varieties have poor cold tolerance and thus have low cultivation safety at low temperatures. However, it is important to select improved lines through generational progress because there are some lines that still have a certain level of cold tolerance among them.

• Research in Plant Disease
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• v.12 no.3
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• pp.158-163
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• 2006

Sclerotinia rot caused by Sclerotinia sclerotiorum frequently causes serious and unpredicable yield losses of the leaves of perilla growing under structured cultivation as vegetable in Korea. Temperature for mycelial growth ranged from 5 to $30^{\circ}C$ with optimum temperature d $20^{\circ}C$. Sclerotia were formed fewer at low temperature, but their dry weight was heavier than that at high temperature. The apothecia were formed from the sclerotia that buried up to 3 cm soil depth at $15^{\circ}C$ in moisture condition. The incidence of perilla Sclerotinia rot caused by S. sclerotiorum was observed throughout the growing season at greenhouse. The occurrence of this disease was especially severe from January to February of low temperature period. The average incidence rates of this disease was up to 15%. The significant occurrence of this disease was showed mainly in the continuous cropping field for more than five years. The incidence of this disease increased according to the increase of continuous cropping year. The incidence rates of this disease reached up to 20% in the continuous cropping field for ten years. Also it was firstly investigated the natural infection caused by S. sclerotiorum on weed plants, Gnaphalium affine and Mazus pumilus in farmer's field. The casual fungus showed pathogenicity on 11 weed plants species tested, and more severe pathogenicity on G. affine, Latuca indica and Ixeris dentata included in the family Compositae. This result suggests that effective crop rotation and weed eradication can be the method for organic control of perilla sclerotinia rot, and sudden outbreaks of this disease on perilla growing under structure after paddy rice call be explained by the presence of weed hosts.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.114-114
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• 2012

Metal-oxide-semiconductor field-effect transistors (MOSFETs)의 critical dimension (CD)가 sub 45 nm로 줄어듬에 따라 기존에 gate dielectric으로 사용하고 있는 SiO2에서 발생되는 high gate leakage current 때문에 새로운 high dielectric constant (k) 물질들이 연구되기 시작하였다. 여러 가지 high-k 물질 중에서, aluminum-oxide (Al2O3)는 높은 dielectric constant (~10)와 전자 터널링 barrier height (~2eV) 등을 가지기 때문에 많은 연구가 되고 있다. 그러나 Al2O3를 anisotropic한 patterning을 하기 위해 주로 사용되고 있는 halogen-based 플라즈마 식각 과정에서 나타나는 Al2O3와 하부 layer간의 낮은 식각 selectivity 뿐만 아니라 표면에 발생되는 defect, stoichiometry modification, roughness 변화 등의 많은 문제점들로 인하여 device performance가 감소하기 때문에 이를 해결하기 위한 많은 연구들이 진행중이다. 따라서 본 연구에서는 실리콘 기판위의 atomic layer deposition (ALD)로 증착된 Al2O3를 BCl3/Ar 중성빔을 이용하여 원자층 식각한 후 식각 특성을 분석해 보았다. Al2O3 표면을 BCl3로 absorption시킨 후 Ar 중성빔으로 desorption 시키는 과정에서 volatile한 aluminum-chlorides와 boron oxychloride가 형성되어 layer by layer로 제거됨을 관찰 할 수 있었다.

• Journal of East-West Nursing Research
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• v.5 no.1
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• pp.114-119
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• 2000

This paper reviews the curriculums on the nursing in oriental medicine currently provided by Korean nursing education institutes. As of October 2000, 14 of 48 four-year-system and 40 of 65 three-years system nursing schools provide the various academic courses and programs titled with the nursing care in oriental medicine. Depending on schools, the credit assigned to these courses and programs vary widely ranged from 1 to 8 units. Even in some schools the courses are offered not as a regular credit course but as a part of other courses on time sharing base. It is absolutely insufficient efforts in promoting education on the nursing in oriental medicine. The oriental medicine is basically based on the principles that the most critical factor in promoting health and preventing disease is the process for improving the condition of both physical and mental part of patients. In this context it seems to be an valuable attempt to apply the principles of oriental medicine to the field of nursing care, and to develop the new methods. It is because promoting health, preventing disease, recovering health, alleviating pains are the basic responsibilities of nursing care. The national health policies have been increasingly emphasizing low-cost and high-efficiency just as in economic policies. In terms of cost-effectiveness nursing education in oriental medicine seems to be evaluated as good enough to satisfy these efficiency requirements. As a initial step for promoting and specializing the nursing education in oriental medicine it is absolutely needed to introduce and expand the curriculum on this new field. Increasing concerns about the oriental medicine as the third medical care is the world wide phenomenon now. Considering this trend, current insufficient curriculum on nursing in oriental medicine in education institutes, especially in four-year system nursing school, might be an undesirable phenomenon for future development of nursing education in Korea. In-depth studies about this issue are seriously needed.

• Korean Journal of Materials Research
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• v.17 no.2
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• pp.73-80
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• 2007

For the sub-65 nm CMOS process, it is necessary to develop a new silicide material and an accompanying process that allows the silicide to maintain a low sheet resistance and to have an enhanced thermal stability, thus providing for a wider process window. In this study, we have evaluated the property and unit process compatibility of newly proposed composite silicides. We fabricated composite silicide layers on single crystal silicon from $10nm-Ni_{1-x}Co_x/single-crystalline-Si(100),\;10nm-Ni_{1-x}Co_x/poly-crystalline-\;Si(100)$ wafers (x=0.2, 0.5, and 0.8) with the purpose of mimicking the silicides on source and drain actives and gates. Both the film structures were prepared by thermal evaporation and silicidized by rapid thermal annealing (RTA) from $700^{\circ}C\;to\;1100^{\circ}C$ for 40 seconds. The sheet resistance, cross-sectional microstructure, surface composition, were investigated using a four-point probe, a field emission scanning probe microscope, a field ion beam, an X-ray diffractometer, and an Auger electron depth profi1ing spectroscopy, respectively. Finally, our newly proposed composite silicides had a stable resistance up to $1100^{\circ}C$ and maintained it below $20{\Omega}/Sg$., while the conventional NiSi was limited to $700^{\circ}C$. All our results imply that the composite silicide made from NiCo alloy films may be a possible candidate for 65 nm-CMOS devices.