• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.42.4-43
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• 2018

Most galaxies are believed to evolve through mergers and accretions. In particular, minor mergers and gas accretion appear to play an important role in galaxy evolution in the present-day Universe. Tidally-disrupted debris from such processes remain as diffuse, low-surface brightness structures because the dynamical timescale in the outskirts is significantly longer than that in the central regions. Although these structures will give us useful insight into the mass assembly history of galaxies, it is difficult to detect them due to their faint surface brightness. In order to investigate the structural properties of outskirts in nearby galaxies, we conduct deep and wide-field imaging survey with KMTNet. We present our observing strategy and an optimal data reduction process to recover faint extended features in the images of KMTNet. Using the imaging data of NGC 1291 obtained from KMTNet, we find that a peak-to-peak sky gradient can be reduced less than 0.4-0.6% of the original sky level in the entire image. We also find that we can reach the surface brightness of ${\mu}_{(B,1{\sigma})}$ ~ 29.5, ${\mu}_{(R,1{\sigma})}$ ~ 28.5 mag $arcsec^{-2}$ in one-dimensional profile, that is mainly limited by the uncertainty in the sky determination. It indicates that deep imaging data of KMTNet is suitable to study the extended faint features of nearby galaxies, such as stellar halos, outer disks, and dwarf companions.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.1031-1033
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• 2014

Aim: To investigate the effect of hyperglycemia and hyperinsulinemia on prostate cancer risk. Materials and Methods: This hospital based study was carried out using data retrieved from the register maintained in the Department of Biochemistry of a tertiary care hospital of Kathmandu, Nepal between $31^{st}$ December, 2011 and $31^{st}$ October, 2013. The variables collected were age, serum cholesterol, serum calcium, PSA, fasting blood glucose, serum insulin. Analysis was performed by descriptive statistics and testing of hypothesis using Excel 2003, R 2.8.0, Statistical Package for the Social Sciences (SPSS) for Windows Version 16.0 (SPSS Inc; Chicago, IL, USA) and the EPI Info 3.5.1 Windows Version. Results: Of the total 125 subjects enrolled in our present study, 25 cases were of PCa and 100 were healthy controls. The mean value of fasting plasma glucose was 95.5 mg/dl in cases of prostatic carcinoma and the mean value of fasting plasma insulin was $5.78{\mu}U/ml$ (p value: 0.0001*). The fasting insulin levels ${\mu}U/ml$ were categorized into the different ranges starting from ${\leq}2.75$, >2.75 to ${\leq}4.10$, >4.10 to ${\leq}6.10$, > $6.10{\mu}U/ml$. The maximum number of cases of prostatic carcinoma of fasting insulin levels falls in range of > $6.10{\mu}U/ml$. The highest insulin levels (> $6.10{\mu}U/ml$) were seen to be associated with an 2.55 fold risk of prostatic carcinoma when compared with fasting insulin levels of (< $2.75{\mu}U/ml$). Conclusions: Elevated fasting levels of serum insulin appear to be associated with a higher risk of prostate cancer.

• Journal of Navigation and Port Research
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• v.26 no.4
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• pp.435-440
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• 2002

The quantitative assessment of the effect of the residual stress on fracture behavior was executed by some experiment and numerical analysis. First of all, artificial residual stresses were imposed on CT(Compact Tension) specimens by local heating using gas torch, and an appropriate distribution of residual stresses was obtained by thermal elastic-plastic FE analysis. To certify the result of the FE analysis, an experimental measurement was performed in accordance with ASTM standard. Fracture toughness test was executed on the several types of specimens. The first type was the specimen without residual stresses, and the others had different peak value of compressive residual stress at crack front via controlling the heat flux. All the test results were presented on th J resistance(JR) curves and discussed to verify the effect of compressive residual stresses on fracture behavior.

• Economic and Environmental Geology
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• v.49 no.5
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• pp.411-415
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• 2016

In this preliminary study, we assessed the toxicity of domestic bentonites using environmental toxicity testings of seed germination and bacterial bioluminescence. In cases of tested bulk bentonite samples, following ranges of toxicity were observed: -3 ~ 95% bioluminescence, 7.1 ~ 92.1% Lactuca germination. Similar results were also observed among tested other seeds, except seed Raphanus. No significant correlations between toxicity and metals contents of bentonite extractants were observed throughout this investigation. Interestingly, distinct different effects were observed according to bentonite colors (blue $67{\pm}8.7%$, pink $27{\pm}10.4%$, brown $58{\pm}14.5%$).

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.277-281
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• 2006

Fourier transform - infrared spectroscopy (FT-IR) provides biochemical profiles containing overlapping signals from a majority of the compounds that are present when whole cell extracts are analyzed. We attempted to determine the ripeness of strawberry fruit flesh by FT-IR. Fruit ripeness was divided into four developmental stages based on fruit skin color: 'yellow-green', 'pink-green', 'pink', and 'red' stages. Principal component analysis of FT-IR data of inside fruit flesh extracts clustered samples of four different developmental stages into three discrete groups: (1) 'yellow-green' group, (2) 'pink-green' group, and (3) 'pink' and 'red' group. The most remarkable difference between four different developmental stages was found in the carbohydrate fingerprint region $(1,000-1,100cm^{-1})$ of the FT-IR spectrum, indicating that differences in carbohydrate compounds represented the ripeness of strawberry fruit. Overall results indicate that FT-IR in combination with PCA enables discrimination of the ripeness of strawberry fruit flesh.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.24 no.4
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• pp.172-179
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• 1988

A cartridge type hydraulic logic valve consists of simple two port valve whose poppet is closed or opened by means of pressure signal of a pilot line. Accordingly, the logic valve can be used not only for direction, flow and pressure control purpose but also for versatile function valve which enables all above mentioned functions. In addition, the valve has little internal leakage and pressure loss, superior response characteristics and easiness in making small block type valve. The above mentioned good performances being recognized recently, the logic valve has been used widely in the large scale hydraulic system such as a hydraulic press system, for the performance requirements of high speed operation and precise control characteristics. However, there are scarce reports until now, except for a few ones from Aachen Institute of Technology in West Germany, so it is necessary to be studied on development and investigation for practical application. This paper showed that the static and dynamic characteristics of a logic valve when the logic valve is used for directional control, to investigate the relations between the valve operating characteristics and the valve design conditions. From the above mentioned procedure, it was ascertained that the valve operation characteristics obtained by numerical analysis showed good agreements with experimental results. The representative results obtained are as follows; 1. During the valve is closing, the poppet velocity is almost constant in the logic valve. 2. The pilot pressure P sub(3) and the resistance R in the pilot line have much influences on the valve operation time. 3. Spring strength have not such a severe influence on the valve operating time. 4. The operation characteristics of the logic valve can be estimated with good accuracy comparatively by numerical analysis with the equations describing poppet motion.

• Korean Journal of Veterinary Service
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• v.39 no.2
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• pp.131-136
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• 2016

Clostridium novyi (C. novyi) is a gram positive, non-capsulated, motile, obligatory anaerobe that produces endospores. Both C. novyi type A and B produce a bacteriophage encoded lethal alpha toxin which belongs to a family of large clostridial cytotoxins. These large clostridial cytotoxins of C. novyi bind to the uncharacterized receptors on host vascular endothelial cells, which leads to the loss of integrity of the vascular endothelium with subsequent edema, refractory hypotension, organ failure, and sudden death. A total of 13 sudden death cases were submitted to Chonbuk National University-Veterinary Diagnostic Center between June and October, 2015. The samples, mainly liver, were collected in sterile vials after necropsy and processed within 12~24 hours for diagnosis, isolation and identification of C. novyi. All of the 4 gram positive samples showed amplification by PCR. Out of 4 positive samples, 3 were detected to be C. novyi type B and 1 was detected as C. novyi type A. Based on the 16S rDNA sequence analysis, 1 case (150564) showed 99% similarity with C. novyi type A while other 3 cases (150388, 150557 and 150775) presented 99% similarity with C. novyi type B. Based on the results, C. novyi was found to be prevalent in Korean pig farms and causes sudden death to finishing pigs or sows during summer season. Thus, C. novyi should be considered for differential diagnosis on sudden death cases during the summer season.

• Korean Journal of Medicinal Crop Science
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• v.17 no.1
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• pp.54-60
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• 2009

This study was performed to improve immune activities of Rubus coreanus Miquel by encapsulation of nanoparticles. Immuno-activities of R. coreanus were investigated through aqueous extracts associated with process of water at $60^{\circ}C$. It showed high promotion of human B and T cells growth about 50%, compared to the case of other conditions. The secretion of IL-6 and TNF-${\alpha}$ was also enhanced as $2.44{\times}10^{-4}$pg/cell and $1.94{\times}10^{-4}$pg/cell, results by adding nano samples. NK cell activation was improved up to 29% higher than the conventional extraction process. The secretion of NO from macrophage showed 14.9 ${\mu}M$ on the nano-encapsulation process extracts, which was higher than others. The size of nanoparticles was in the range of 50${\sim}$300 nm, which can effect the penetration into the cells. It was clearly observed by real time confocal microscope.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.106.2-106.2
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• 2012

Ti-Ni합금은 CsCl구조의 B2상, monoclinic 구조의 B19'(M)상과 rhombohedral 구조의 R상(R)이 나타난다고 알려져 있고, 이들 상의 변태에 의해 열탄성 마르텐사이트와 응력유기 마르텐사이트에 의한 형상기억효과와 초탄성 효과를 가지고 있다. 또한 Ti-Ni 합금은 우수한 형상기억특성을 가질 뿐만 아니라 생체적합성, 가공성 및 내식성 등이 뛰어나 공업분야 및 생체분야에서 폭 넓게 활용되고 있다. Ti-Ni합금의 형상기억특성은 냉간가공 후 어닐링 처리의 온도와 시간에 따른 matrix 내 Ni의 농도, 석출물의 밀도와 크기, 전위밀도와 전위주위의 응력장에 의해 영향을 받는다고 알려져 있다. 본 연구에서는 Ti-Ni합금의 형상기억 특성 및 변태온도에 미치는 영향을 조사하기 위해 다양한 냉간가공률의 시료를 제작하여 다양한 온도에서 Annealing 처리를 하여 냉간가공률 및 Annealing 온도가 형상기억특성에 미치는 영향을 조사하였다. Ti-50.4 at.% Ni 합금은 진공 아크 용해로에서 용해 하였으며, 용해된 Ingot는 열간단조 및 열간 압출한 후 냉간 인발과 중간온도에서 어닐링을 반복하면서 직경 0.5mm의 선재로 만들었다. 최종적으로 제작한 선재의 냉간가공률은 9.5%, 18.2%, 34.5%, 45% 이었다. 각 시편은 5X10-5torr의 진공으로 석영관에 진공 봉입하여 각각 673K, 723K, 783K에서 1hr 열처리 하였다. 합금의 형상기억특성과 변태온도는 DSC에 의해 조사되었다. DSC 측정 결과, 냉간가공률이 증가함에 따라 마르텐사이트 변태 온도는 감소하였고, 어닐링 온도가 증가함에 따라 마르텐사이트 변태 온도는 증가하였다. 또한 가공률이 증가하여도 R상 변태온도는 큰 변화가 없었고, Annealing온도가 증가함에 따라 R상 변태온도는 감소하였다. 또한, 형상기억특성은 인장시험기를 이용한 정하중 열싸이클 테스트를 이용하여 평가 하였다. 냉간 가공률이 증가함에 따라 안정한 형상기억특성을 나타내었다.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.569-574
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• 2014

Inverted bulk hetero-junction polymer solar cells (iPSC) composed of P3HT/PC61BM blends on the ZnO modified with benzoic acid derivatives-based self-assembled monolayers (SAM) are fabricated. Compared with the device using the pristine ZnO, the devices with ZnO surface modified SAMs derived from benzoic acid such as 4-(diphenylamino)benzoic acid (DPA-BA) and 4-(9H-carbazol-9-yl)benzoic acid (Cz-BA) as an electron transporting layer show improved the performances. It is mainly attributed to the favorable interface dipole at the interface between ZnO and the active layer, the eective passivation of the ZnO surface traps, decrease of the work function and facilitating transport of electron from PCBM to ITO electrode. The power conversion eciency (PCE) of iPSCs based on DPA-BA and Cz-BA treated ZnO reaches 2.78 and 2.88%, respectively, while the PCE of the device based on untreated ZnO is 2.49%. The open circuit voltage values ($V_{oc}$) of the devices with bare ZnO and SAM treated ZnO are not much different. Whereas, higher the fill factor (FF) and lower the series resistance ($R_s$) are obtained in the devices with SAMs modification.