• Industrial Engineering and Management Systems
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• v.8 no.1
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• pp.22-28
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• 2009

We consider facility layout problems, where mn facility units are assigned into mn cells. These cells are arranged into a rectangular pattern with m rows and n columns. In order to solve this cell type facility layout problem, many approximation algorithms with improved local search methods were studied because it was quite difficult to find exact optimum of such problem in case of large size problem. In this paper, new algorithms based on Simulated Annealing (SA) method with two neighborhood generation methods are proposed. The new neighborhood generation method adopts the exchanging operation of facility units in accordance with adjacent preference. For evaluating the performance of the neighborhood generation method, three algorithms, previous SA algorithm with random 2-opt neighborhood generation method, the SA-based algorithm with the new neighborhood generation method (SA1) and the SA-based algorithm with probabilistic selection of random 2-opt and the new neighborhood generation method (SA2), are developed and compared by experiment of solving same example problem. In case of numeric examples with problem type 1 (the optimum layout is given), SA1 algorithm could find excellent layout than other algorithms. However, in case of problem type 2 (random-prepared and optimum-unknown problem), SA2 was excellent more than other algorithms.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.629-635
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• 2014

This paper describes propagation characteristics obtained by considering semiconducting screen and cross-bonding in underground transmission cables. The semiconducting screen of power cable has effect on propagation characteristics including attenuation, velocity and surge impedance. However, it is very difficult to apply the semiconduction screen for EMTP model because of the number of conductors limitation. Therefore, CIGRE WG 21-05 proposed advanced insulation structure and analysis technique of simplified approach including inner and outer semiconducting screen. In this paper, the various propagation characteristics analyse using this structure and technique for 154kV XLPE $2000mm^2$ cable. The frequency independent model of EMTP CABLE PARAMETER is used for just pattern analysis of propagation characteristics. For exact data analysis, the frequency dependent model of J-marti is used for EMTP modeling. From these result, various propagation characteristics of 154kV XLPE $2000mm^2$ cable according to semi conducting screen consideration, frequency range, cable length and pulse width are analysed. In addition, in this paper, the effects of cross-bonding are also variously discussed according to cross-bonding methods, direct connection and impedance of lead cable.

• The Korean Journal of Cytopathology
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• v.19 no.2
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• pp.173-177
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• 2008

Epithelial-myoepithelial carcinoma (EMC) is a rare low grade malignant tumor of the salivary glands and it shows a characteristic biphasic population of epithelium and myoepithelium. It shows various cytologic and histologic features, so making an exact diagnosis is difficult. We report here on two cases of epithelial-myoepithelial carcinoma arising from the parotid gland and we compare the cytologic findings of the aspirated samples with the histologic findings of the tumors. We think the finding of mixed pattern of large, clear myoepithelia and small epithelia is the most valuable finding in the diagnosis of EMC.

• Safety and Health at Work
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• v.7 no.2
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• pp.120-123
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• 2016

Background: To assess in a laboratory setting the ability to stay awake in a sample of workers of an Italian hospital and to investigate the association between that ability and the risk of occupational injury. Methods: Nine workers at the University Hospital of Udine who reported an occupational injury in the study period (cases), and seven noninjured workers (controls) underwent a polysomnography and four 40-minute maintenance of wakefulness tests (MWT). Differences in sleep characteristics and in wakefulness maintenance were assessed using Wilcoxon's rank sums tests and Fisher's exact tests. Results: Controls had greater sleep latency, lower total sleep time, fewer leg movements, and a higher percentage ratio of cycling alternating pattern, were more likely not to fall asleep during the MWT and were less likely to have two or more sleep onsets. Although not all the differences reached statistical significance, cases had lower sleep onset times in Trials 1-3. Conclusion: In the literature, the evidence of an association between MWT results and real life risk of accidents is weak. Our results suggest a relationship between the MWT results and the risk of injury among hospital workers.

• Journal of Yeungnam Medical Science
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• v.39 no.3
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• pp.181-189
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• 2022

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative condition characterized by loss of motor neurons, resulting in motor weakness of the limbs and/or bulbar muscles. Pain is a prevalent but neglected symptom of ALS, and it has a significant negative impact on the quality of life of patients and their caregivers. This review outlines the epidemiology, clinical characteristics, underlying mechanisms, and management strategies of pain in ALS to improve clinical practice and patient outcomes related to pain. Pain is a prevalent symptom among patients with ALS, with a variable reported prevalence. It may occur at any stage of the disease and can involve any part of the body without a specific pattern. Primary pain includes neuropathic pain and pain from spasticity or cramps, while secondary pain is mainly nociceptive, occurring with the progression of muscle weakness and atrophy, prolonged immobility causing degenerative changes in joints and connective tissue, and long-term home mechanical ventilation. Prior to treatment, the exact patterns and causes of pain must first be identified, and the treatment should be tailored to each patient. Treatment options can be classified into pharmacological treatments, including nonsteroidal anti-inflammatory drugs, antiepileptic drugs, drugs for cramps or spasticity, and opioid; and nonpharmacological treatments, including positioning, splints, joint injections, and physical therapy. The development of standardized and specific assessment tools for pain-specific to ALS is required, as are further studies on treatments to reduce pain, diminish suffering, and improve the quality of life of patients with ALS.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.4
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• pp.195-201
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• 2022

For a efficient distance education environment, the need for correct problem recommendation guides considering the learner's exact learning pattern is increasing. In this paper, we study block chain based smart contract technology to suggest a method for presenting the optimal problem recommendation path for individual learners based on the data given by situational weights to the problem patterns of learners collected in the distance education environment. For the performance evaluation of this study, the learning satisfaction with the existing similar learning environment, the usefulness of the problem recommendation guide, and the learner data processing speed were analyzed. Through this study, it was confirmed that the learning satisfaction improved by more than 15% and the learning data processing speed was improved by more than 20% compared to the existing learning environment.

• Geomechanics and Engineering
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• v.30 no.5
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• pp.423-435
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• 2022

Ground vibration generated repeatedly in blasting tunnel excavation sites is known to be one of the major hazards induced by blasting operations. Various studies have been conducted to minimize these hazards, both theoretical and empirical methods using electronic detonator, the deck charge method, the center-cut method among others Among these various existing methods for controlling the ground vibration, in this study, we investigated the cut method. In particular, we analyzed and compared the V-cut method, which is commonly used in tunnel blasting, to the double-drilled parallel method, which has recently been introduced in tunnel excavation site. To understand the rock fragmentation efficiency as well as the ground vibration controllability of the two methods, we performed in-situ field blasting tests with both cut methods at a tunnel excavation site. Additionally, numerical analysis by FLAC3D has been executed for a better understanding of fracture propagation pattern and ground vibration generation by each cut method. Ground vibration levels, by PPVs measured in field blasting tests and PPVs estimated in numerical simulations, showed a lower value in the double-drilled parallel compared with the V-cut method, although the exact values are quite different in field measurement and numerical estimation.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.35 no.4
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• pp.106-122
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• 2022

Objectives : In this study, we aimed to analyze the latest knowledge of pityriasis rosea(PR) through oriental-western medical review on PR. Methods : We searched Pubmed, CNKI, and OASIS to select papers related to the cause, mechanism, diagnosis, classification, treatment, and herbal treatment of PR. Results : The results are as follows. 1. Although the exact cause of PR is not known, it has recently been found that reactivation of latent human herpesvirus-6 and human herpesvirus-7 infection is a possible etiology. Most patients require emollients, antihistamines, topical steroids, and macrolides. Acyclovir, and narrow-band UVB therapy are also used. 2. The cause and mechanism of PR in Chinese and Korean medicine can be mainly summarized as wind-heat, blood heat, and blood deficiency and wind-dryness. Most of the herbal medicine used have the effects of clearing heat, cooling the blood, detoxifying, dispelling wind, relieving itching, nourishing blood, and moistening dryness. Conclusions : In Chinese and Korean medicine, it is necessary to organize the representative prescriptions according to pattern identification, and it is also necessary to study the atypical types of PR and its treatment methods. It is thought that research on oriental and western combination therapy should be continuously conducted, and efforts to develop Korean medicine formulations are needed to revitalize clinical research in Korea.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.1
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• pp.16-22
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• 2023

In a solar cell, degradation refers to the decrease in performance parameters caused by defects originated due to various causes. During the fabrication process of solar cells, degradation is generally related to the processes such as passivation or firing. There exist sources of many types of degradation; however, the exact cause of Light and elevated Temperature Induced Degradation (LeTID) is yet to be determined. It is reported that the degradation and the regeneration occur due to the recombination of hydrogen and an arbitrary substance. In this paper, we report the deposition of Al₂O₃ and SiN_X on silicon wafers used in the Passivated Emitter and Rear Contact (PERC) solar structure and its degradation pattern. A higher degradation rate was observed in the sample with single layer of Al₂O₃ only, which indicates that the degradation is affected by the presence or the absence of a passivation thin film. In order to alleviate the degradation, optimization of different steps should be carried out in consideration of degradation in the solar cell fabrication process.

• Biomedical Science Letters
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• v.29 no.4
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• pp.280-286
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• 2023

In humic substances, fulvic acid (FA) is a subclass of diverse compounds known as humic substances, which are by-products of organic degradation from microorganisms. FA can suppress the proliferation of tumor cells. Despite numerous studies, the exact mechanism for the various effects of FA is not clearly understood. Based on results demonstrating anti-proliferation effects on human cancer, we investigated whether FA has similar effects on lung cancer in this study. Firstly, the anti-cancer effect of FA in pulmonary epithelial tumor cell lines (TC-1 cells) was examined by confirming its inhibitory effect on the cell proliferation of TC-1 cells. TC-1 cell proliferation was reduced by FA on a dose-dependent and time-dependent manner. After 24 hours of FA treatment, cell morphological changes such as cell volume decrease, non-adherence and increased number of apoptotic cells were clearly observed. In addition, FA induced a DNA ladder pattern by increased of DNA fragments in TC-1 cells. In the intracellular regulatory pathway by FA, we confirmed that FA induced the reduction of the anti-apoptotic protein, Bcl-2 protein levels. These results indicate that FA has anticancer effect by inducing intracellular apoptotic pathway. Further research on the mechanism of anticancer effects will be basic data for the development of potential anticancer drugs.