• Journal of Korea Multimedia Society
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• v.22 no.12
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• pp.1376-1384
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• 2019

The cosmetic and behavioral aspects of aging have become increasingly evident over the years. Physical aging in people can easily be observed on their face, posture, voice, and gait. In contrast, bone aging only becomes apparent once significant bone degeneration manifests through degenerative bone diseases. Therefore, a more accurate and timely assessment of bone aging is needed so that the determinants and its mechanisms can be more effectively identified and ultimately optimized. This study proposed a deep learning approach to assess the bone age of an adult using whole-body bone scintigraphy. The proposed approach uses multiple inputs deep neural network architectures using a loss function, called mean-variance loss. The data set was collected from Chonnam National University Hwasun Hospital. The experiment results show the effectiveness of the proposed method with a mean absolute error of 3.40 years.

• Interdisciplinary Bio Central
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• v.4 no.4
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• pp.14.1-14.6
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• 2012

Splice site prediction in DNA sequence is a basic search problem for finding exon/intron and intron/exon boundaries. Removing introns and then joining the exons together forms the mRNA sequence. These sequences are the input of the translation process. It is a necessary step in the central dogma of molecular biology. The main task of splice site prediction is to find out the exact GT and AG ended sequences. Then it identifies the true and false GT and AG ended sequences among those candidate sequences. In this paper, we survey research works on splice site prediction based on support vector machine (SVM). The basic difference between these research works is nucleotide encoding technique and SVM kernel selection. Some methods encode the DNA sequence in a sparse way whereas others encode in a probabilistic manner. The encoded sequences serve as input of SVM. The task of SVM is to classify them using its learning model. The accuracy of classification largely depends on the proper kernel selection for sequence data as well as a selection of kernel parameter. We observe each encoding technique and classify them according to their similarity. Then we discuss about kernel and their parameter selection. Our survey paper provides a basic understanding of encoding approaches and proper kernel selection of SVM for splice site prediction.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1690-1698
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• 2006

In order to investigate the effect of dissolved oxygen (DO) level on AVM $B_{1a}$ production by a high yielding mutant of Streptomyces avermitilis, five sets of bioreactor cultures were performed under variously controlled DO levels. Using an online computer control system, the agitation speed and aeration rate were automatically controlled in an adaptive manner, responding timely to the oxygen requirement of the producer microorganism. In the two cultures of DO limitation, the onset of AVM $B_{1a}$ biosynthesis was observed to casually coincide with the fermentation time when oxygen-limited conditions were overcome by the producing microorganism. In contrast, this phenomenon did not occur in the parallel fermentations with DO levels controlled at around 30% and 40% throughout the entire fermentation period, showing an almost growth-associated mode of AVM $B_{1a}$ production: AVM $B_{1a}$ biosynthesis under the environments of high DO levels started much earlier than the corresponding oxygen-limited cultures, leading to a significant enhancement of AVM $B_{1a}$ production during the exponential stage. Consequently, approximately 6-fold and 9-fold increases in the final AVM $B_{1a}$ production were obtained in 30% and 40% DO-controlled fermentations, respectively, especially when compared with the culture of severe DO limitation (the culture with 0% DO level during the exponential phase). The production yield ($Y_{p/x}$), volumetric production rate (Qp), and specific production rate (${\bar{q}}_p$) of the 40% DO-controlled culture were observed to be 14%, 15%, and 15% higher, respectively, than those of the parallel cultures that were performed under an excessive agitation speed (350 rpm) and aeration rate (1 vvm) to maintain sufficiently high DO levels throughout the entire fermentation period. These results suggest that high shear damage of the high-yielding strain due to an excessive agitation speed is the primary reason for the reduction of the AVM $B_{1a}$ biosynthetic capability of the producer. As for the cell growth, exponential growth patterns during the initial 3 days were observed in the fermentations of sufficient DO levels, whereas almost linear patterns of cell growth were observed in the other two cultures of DO limitation during the identical period, resulting in apparently lower amounts of DCW. These results led us to conclude that maintenance of optimum DO levels, but not too high to cause potential shear damage on the producer, was crucial not only for the cell growth, but also for the enhanced production of AVM $B_{1a}$ by the filamentous mycelial cells of Streptomyces avermitilis.

• BMB Reports
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• v.45 no.11
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• pp.647-652
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• 2012

We previously reported that MSTO-211H cells have a higher capacity to regulate Nrf2 activation in response to changes in the cellular redox environment. To further characterize its biological significance, the response of Nrf2, a transcription factor that regulates ARE-containing genes, on the synergistic cytotoxic effect of clofarabine and resveratrol was investigated in mesothelioma cells. The combination treatment showed a marked growth-inhibitory effect, which was accompanied by suppression of Nrf2 activation and decreased expression of heme oxygenase-1 (HO-1). While transient overexpression of Nrf2 conferred protection against the cytotoxicity caused by their combination, knockdown of Nrf2 expression using siRNA enhanced their cytotoxic effect. Pretreatment with Ly294002, a PI3K inhibitor, augmented the decrease in HO-1 level by their combination, whereas no obvious changes were observed in Nrf2 levels. Altogether, these results suggest that the synergistic cytotoxic effect of clofarabine and resveratrol was mediated, at least in part, through suppression of Nrf2 signaling.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.65-70
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• 2016

Lung cancer is one of the most common malignancies in the world. Its incidence and mortality rates are on the rise in Pakistan. However, epidemiological studies to identify common lung cancer determinants in the Pakistani population have been limited. In this study, data of 440 cases and 323 controls were collected from different hospitals in Peshawar and Islamabad, along with information about socio-demographic factors including age, sex and smoking. Univariate and multi-factorial analyses of socio-demographic factors in association with each other were also performed. Overall survival analysis highlighted that, out of 440 patients in the lung cancer dataset, 204 people were uncensored with a median survival time of 13 months (95% CI=12-18). There were 41 femaleand 399 male patients. Differences were observed between length of survival in the males and females (${\chi}12$ = 6.1; p-value = 0.01). Gender was observed to be significantly related to survival (p-value< 0.01), with better survival in females (hazard ratio=2). Cox regression was extended to adjust for the covariate age (z = 2.5; p-value = 0.02). Survival analysis was also performed on the basis of smoking groups (current smokers, former smokers and never smoked individuals) and smoking duration (smoking duration >10 years, <10 years and never smoked). Smoking duration was significantly associated with survival (p-value < 0.01), with better survival in never smokers in comparison to both smoking for greater or less than 10 years. Strong associations were observed for smoking group with duration greater than 10 years, OR=6.1(3.9-9.5) on univariate and multifactorial analysis OR=11.3(CI=6.8-19.3).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.5
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• pp.15-23
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• 2002

For molecular dynamics requires high-performance computers or supercomputers to handle huge amount of computation, it is not until recent days that the application of molecular dynamics to materials fracture simulations draw some attention from many researchers. With the recent advent of high-performance computers, computation intensive methods become more tractable than ever. However, carrying out materials simulation on high-performance computers costs too much in general. In this study, a PC cluster consisting of multiple commodity PCs is established and computer simulations of materials with cracks are carried out on it via molecular dynamics technique. The effect of the number of nodes, speedup factors, and communication time between nodes are measured to verify the performance of the PC cluster. Upon using the PC cluster, materials fracture simulations with more than 50,000 molecules are carried out successfully.

• Genomics & Informatics
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• v.5 no.3
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• pp.102-106
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• 2007

Radiofrequency (RF) radiation at the frequency of mobile phones has been not reported to induce cellular responses in in vitro and in vivo models. We exposed HEI-OC1, conditionally-immortalized mouse auditory cells, to RF radiation to characterize cellular responses to 1763 MHz RF radiation. While we could not detect any differences upon RF exposure, whole-genome expression profiling might provide the most sensitive method to find the molecular responses to RF radiation. HEI-OC1 cells were exposed to 1763 MHz RF radiation at an average specific absorption rate (SAR) of 20 W/kg for 24 hr and harvested after 5 hr of recovery (R5), alongside sham-exposed samples (S5). From the whole-genome profiles of mouse neurons, we selected 9 differentially-expressed genes between the S5 and R5 groups using information gain-based recursive feature elimination procedure. Based on support vector machine (SVM), we designed a prediction model using the 9 genes to discriminate the two groups. Our prediction model could predict the target class without any error. From these results, we developed a prediction model using biomarkers to determine the RF radiation exposure in mouse auditory cells with perfect accuracy, which may need validation in in vivo RF-exposure models.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.505-508
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• 1989

A computer simulation code of UV preionized discharge KrF laser is developed, including time dependent circuit equations, boltzmann equations, and plasma kinetic equations for various atomic and molecular species. Rate constants for electron collision processes are calculated with a boltzmann equations as a function of E/N. In this study, we studied mainly the $KrF^*$ formation process, relaxation process, and the 248nm absorption process as a function of charging voltage.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.731-734
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• 2011

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.11a
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• pp.105-110
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• 1994

분자 모델링은 Molecular Mechanics 라는 empirical force field를 사용하여 여러 가지 분자들의 3차원적 구조를 구하고, 이로부터 이 분자들의 물리적, 화학적 성질들을 계산하고, Computer Graphics를 사용하여 형상화하는 전반적인 연구활동을 의미한다. 이러한 연구활동의 출발점은 실제의 분자와 가장 가까운 3차원적 분자구조를 얻는 것이다. 여러 가지 가능한 방법을 통하여(양자역학적 계산 혹은 X-ray Database 검색등) 최적의 구조를 얻은 후, 이 구조를 사용하여 관심 있는 여러가지 물리적, 화학적 성질들을 계산할 때, 비로소 실험결과를 설명할 수 있게 되고, 이를 토대로 하여 새로운 분자의 Design 이 가능할 수 있을 것이다.