• Journal of Power Electronics
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• v.19 no.1
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• pp.146-157
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• 2019

The inverter is an essential part of permanent magnet synchronous motor (PMSM) drive systems. The performance of an inverter is greatly influenced by its modulation strategy. Using a proper management of modulation strategies can guarantee high performance from a PMSM under various speed conditions. Switching between modulations is a pivotal technique that determines the performance of a PMSM. Most works on hybrid methods focus on two-level induction motors drive systems. In this paper, in order to improve the performance of PMSMs under various speed conditions, a hybrid method of a pulse width modulation (PWM) control scheme based on a neutral-point-clamped (NPC) three level topology was proposed. This hybrid PWM modulation comprised space vector PWM (SVPWM) and selective harmonic elimination PWM (SHEPWM). Under low speed conditions, the SVPWM is employed to cause the PMSM to start smoothly, and to obtain a rapid response from the control system. Under high speed conditions, the SHEPWM is employed to reduce the switching frequency and to eliminate particular current harmonics. Moreover, the harmonic characteristics of different modulations are analyzed to obtain a smooth transition between the SHEPWM and the SVPWM. Experimental and simulation results indicated the effectiveness of the proposed control method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.4
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• pp.61-70
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• 2005

We propose and implement a flexible secure peer-to-peer(P2P) file sharing scheme which can be used for data sharing among closed user group (CUG) members. When a member wants to share data, notification messages are sent to the members with whom the member wants to share data. Each notification message includes one-time password encrypted with the receiver's public key. A member who received the notification message can download the data by using the one-time password. The proposed scheme provides selective sharing, download confirmation and efficient storage management. In terms of security, the proposed scheme supports authentication, entity privacy, replay attack protection and disguise prevention. We also implement the proposed system and find that the system is very useful among P2P service of closed user groups.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.3
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• pp.261-268
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• 2021

Hemophilia A is a hemorrhagic disease caused by coagulation factor VIII deficiency. In head and neck cancer surgery, especially during a reconstructive one, complications can occur. These include hematomas due to bleeding which can then lead to flap ischemia, necrosis, and impaired wound healing. There are fewer cases of reconstructive surgery in patients with hemophilia A. Here in we report, a reconstructive surgery that involved mass resection, partial glossectomy (right), selective neck dissection (right, Levels I, II, III, IV), and reconstruction at the lateral arm free flap (left) in a 25-year-old man with hemophilia A. The surgery was successfully performed without any complications after pretreatment with Factor VIII concentrate, which has not been reported earlier.

• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.71-75
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• 2021

The article discusses the dead reckoning of the traveled path based on the analysis of the video data stream coming from the optoelectronic surveillance devices; the use of relief data makes it possible to partially compensate for the shortcomings of the first method. Using the overlap of the photo-video data stream, the terrain is restored. Comparison with a digital terrain model allows the location of the aircraft to be determined; the use of digital images of the terrain also allows you to determine the coordinates of the location and orientation by comparing the current view information. This method provides high accuracy in determining the absolute coordinates even in the absence of relief. It also allows you to find the absolute position of the camera, even when its approximate coordinates are not known at all.

• Asia-Pacific Journal of Business
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• v.10 no.3
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• pp.143-151
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• 2019

Whether export-market prioritization is effective on financial performance is a controversial issue. Nevertheless, few studies have addressed this issue. The present study attempted to explicate the effects of exporters' market prioritization on their superior financial performance. Based prominently on the market-segmentation theory and the relationship-marketing theory, the current study developed propositions of whether export-market prioritization is economically reasonable. It is posited that export-market prioritization postively influences buyer satisfaction in a primary market; that export-market prioritization negatively affects on buyer satisfaction in a secondary market; that export market prioritization reduces costs in relation to export marketing and sales; that buyer satisfaction positively influences buyer loyalty for both buyers in primary markets and ones in secondary markets; that buyer loyalty positively influences share of wallet for both buyers in primary markets and ones in secondary markets; and that share of wallet positively influences sales per buyer for both buyers in primary markets and ones in secondary markets. Thus, exporters should identify suitable export-market segments and prioritize export markets. The present study suggested that exporters monitor market profitability, assess the quality of buyer information, and conduct selective organizational alignment in order to develop a prioritization strategy.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.429-438
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• 2020

The emergence of multi-drug resistant, pathogenic methicillin-resistant Staphylococcus aureus (MRSA) is a threat to global health and has created a need for novel functional therapeutic agents. In this study, we evaluated the underlying mechanisms of the anti-MRSA effect of an azaphilone pigment, sclerotiorin (SCL) from Penicillium sclerotiorum. The antimicrobial activity of SCL was evaluated using agar disc diffusion, broth microdilution, time-kill assays and biophysical studies. SCL exhibits selective activity against Gram positive bacteria including MRSA (range, MIC = 128-1028 ㎍/ml) and exhibited rapid bactericidal action against MRSA with a > 4 log reduction in colony forming units within three hours of administration. Biophysical studies, using fluorescent probes and laser or electron microscopy, demonstrated a SCL dose-dependent alternation in membrane potential (62.6 ± 5.0.4% inhibition) and integrity (> 95 ± 2.3%), and the release of UV260 absorbing materials within 60 min (up to 3.2 fold increase, p < 0.01) of exposure. Further, SCL localized to the cytoplasm and hydrolyzed plasmid DNA. While in vitro checkerboard studies revealed that SCL potentiated the antimicrobial activity of topical antimicrobials such as polymixin, neomycin, and bacitracin (Fractional Inhibitory Concentration Index range, 0.26-0.37). Taken together these results suggest that SCL targets the membrane and DNA of MRSA to facilitate its anti-MRSA antimicrobial effect.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.993-1003
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• 2021

The contribution made by the tourism sector is strategic enough to provide job opportunities and increase the state's foreign exchange which will be followed by development in the information and technology sectors. The population of this study includes all domestic tourists who visit the Batu City Angkut Museum over 17 years of age and who have obtained information via eWOM from other tourists. Based on the measurement, a minimum of 160 respondents must be selected as the research sample. Non-probability sampling techniques are used to select samples. Social media had been used by companies to provide information, services, and products related to tourism, and it was utilized by tourists to share information about their traveling experiences. Nowadays, tourists have become more selective and critical in selecting their destinations as they have become good observant in finding adequate information about certain destinations before deciding to visit the place. This reaction can be influenced by positive eWOM communication, positive image, and trust given to certain tourist destinations. Therefore, improving the number of visits requires the management of certain tourism service companies to apply proper marketing strategy and provide various advantages and best service quality to attract more visitors and give satisfaction to visitors.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.142-150
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• 2021

Open-channel SSD is a new type of Solid-State Disk (SSD) that improves the garbage collection overhead and write amplification due to physical constraints of NAND flash memory by exposing the internal structure of the SSD to the host. However, the host-level Flash Translation Layer (FTL) provided for open-channel SSDs in the current Linux kernel consumes host memory excessively because it use page-level mapping table to translate logical address to physical address. Therefore, in this paper, we implemente a selective mapping table loading scheme that loads only a currently required part of the mapping table to the mapping table cache from SSD instead of entire mapping table. In addition, to increase the hit ratio of the mapping table cache, filesystem information and mapping table access history are utilized for cache replacement policy. The proposed scheme is implemented in the host-level FTL of the Linux kernel and evaluated using open-channel SSD emulator. According to the evaluation results, we can achieve 80% of I/O performance using the only 32% of memory usage compared to the previous host-level FTL.

• The Journal of Industrial Distribution & Business
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• v.13 no.8
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• pp.1-7
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• 2022

Purpose: The present study concentrates on the issues that affected the employees directly and acted as stress factors. These stress factors affect how the employees perform while undertaking their duties. Furthermore, this study evaluated how the involvement of the corporate counsel affected the company by enhancing the productivity of the employees. Research design, data and methodology: The research design of this research is a literature content analysis and method for data handling should be described, and the resultant combination of the studies should include the consistency measures for every meta-analysis. Specify any risk assessment of bias that may impact the cumulative evidence, such as the publication bias and the selective reporting within studies. Results: The finding shows that change in the location of employees' organizational restructuring and the introduction of new technologies also contributed to significant organizational stress factors. These results show a substantial correlation between the magnitude of the adjustments' effects on employees' performance. Conclusions: The current study strongly concludes that counselors, through their prowess, can analyze and evaluate the stress factors that are evident among the employees and in the organization. Some of these factors may be office layout, organizational codes of ethics, organization rules, and employees' personal challenges.

• Advances in nano research
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• v.13 no.5
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• pp.475-485
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• 2022

Crystalline silicon photovoltaic cells have advantages of zero pollution, large scale and high reliability. A major challenge is that sunlight wavelength with photon energy lower than semiconductor band gap is converted into heat and increase its temperature and reduce its conversion efficiency. Traditional cooling PV method is using water flowing below the modules to cool down PV temperature. In this paper, the idea is proposed to reduce the temperature of the module and improve the energy conversion efficiency of the module through the modulation of the solar spectrum. A spectrally selective nanofilm reflector located directly on the surface of PV is designed, which can reflect sunlight wavelength with low photon energy, and even enhance absorption of sunlight wavelength with high photon energy. The results indicate that nanofilm reflector can reduce spectral reflectivity integral from 9.0% to 6.93% in 400~1100 nm wavelength range, and improve spectral reflectivity integral from 23.1% to 78.34% in long wavelength range. The nanofilm reflector can reduce temperature of PV by 4.51℃ and relatively improved energy conversion efficiency of PV by 1.25% when solar irradiance is 1000 W/m². Furthermore, the nanofilm reflector is insensitive in sunlight's angle and polarization state, and be suitable for high irradiance environment.