• International Journal of Industrial Entomology and Biomaterials
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• v.38 no.1
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• pp.14-17
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• 2019

Oral gargling solution has been used for the control of halitosis. The purpose of this study was to compare the level of hydrogen sulphide concentration between silk oral gargling solution and commercially available oral gargling solution. Total 21 volunteers were included in this study. The relative level of hydrogen sulphide concentration was calculated to the baseline level. In terms of the primary endpoint of the trial, relative level of hydrogen sulphide concentration was $50.84{\pm}33.19%$ with silk group, versus $71.07{\pm}21.83%$ with Listerine group ($P_{non-inferiority}=0.003$). In conclusion, the results of oral gargling with a silk protein for healthy individual were non-inferior to oral gargling with Listerine for hydrogen sulphide concentration reduction.

• Explosives and Blasting
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• v.37 no.1
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• pp.24-33
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• 2019

Recently, Electronic Detonators have gradually increased their performance for various purposes such as vibration control and improved Fragmentation. This study analyzed the vibration estimation equations of electric and electronic detonator blast by comprehensive analysis of the vibration data collected during electric and electronic detonator blast waves at the comparison sites of urban areas, geology and soil conditions, stone quarries and mines in different areas of Korea from June 2017 to December 2018. It has been confirmed that electronic detonator blast can meet the criteria for allowing vibration even if maximum charge weight per delay is increased by 1.5 times compared to the electric detonator blast.

• Journal of the Korean Ceramic Society
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• v.56 no.1
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• pp.65-70
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• 2019

Simple fabrication of a powdered Ge-reduced graphene oxide (Ge-rGO) composite via spray pyrolysis and reduction is introduced herein. Successful incorporation of the rGO nanosheets with Ge hindered the aggregation of Ge and conferred enhanced structural stability to the composite by alleviating the mechanical stress associated with drastic volume changes during repeated cycling. The Li-ion storage performance of Ge-rGO was compared with that of powdered Ge metal. The reversible discharge capacity of Ge-rGO at the $200^{th}$ cycle was $748mA\;h\;g^{-1}$ at a current density of $1.0A\;g^{-1}$ and Ge-rGO showed a capacity of $375mA\;h\;g^{-1}$ even at a high current density of $5.0A\;g^{-1}$. The excellent performance of Ge-rGO is attributed to the structural robustness, enhanced electrical conductivity, and formation of open channels between the rGO nanosheets, which facilitated electrolyte penetration for improved Li-ion diffusion.

• Journal of Positioning, Navigation, and Timing
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• v.8 no.1
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• pp.31-40
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• 2019

In recent years, Intelligent Transport Systems (ITS) and Autonomous Vehicle Technology have actively studied around the world. In order to achieve the purpose of Advanced Driver Assistance System (ADAS) and Autonomous Vehicle Technology, it must be obtained accurate and reliable positioning. However, the problem of positioning in the urban area is a low position accuracy caused by the reduction of the number of visible satellites due to high buildings. In this paper, we analyzed the availability of precise positioning system in urban area are using GPS/BDS integrated system. For this study, GPS and BDS satellite signals were collected using two low-cost receivers in the open sky and a designed software based platform for precise positioning performance analysis. And we analyzed the precise positioning performance by changing the mask angle considering the urban area. From the results, it can be confirmed that the performance of precise positioning of GPS only and BDS only decrease in the environment where mask angle is $40^{\circ}$ to $45^{\circ}$, however, GPS/BDS integrated system maintains high performance of precise positioning.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.31-42
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• 2019

As smartphone H/W performance and mobile communication service have been enhanced, large-capacity 3D modeling files are available in smartphones. Common formats of 3D modeling files include STL (STereoLithography), OBJ (Wavefront file format specification), FBX (Filmbox), and glTF (open GL Transmission Format). Each format has different characteristics depending on the configuration and functions, and formats that are supported are varied depending on the applications. Large-size files are commonly used. The 4th generation mobile communication network secures loading of 3D modeling files and transmission of large-size geometric files in order to provide augmented reality services via smartphones. This paper explains the concepts and characteristics of major 3D file formats such as OBJ, FBX, and glTF. In addition, it compares their performance in a wired web with that in the 4th generation mobile communication network. The loading time and packet transmission in each 3D format are also measured by means of different mobile web browsers (Google Chrome and MS Edge). The experiment result shows that glTF demonstrated the most efficient performance while the loading time of OBJ was relatively excessive. Findings of this study can be utilized in selecting specific 3D file formats for rendering time reduction depending on the mobile web environments.

• The Journal of Industrial Distribution & Business
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• v.13 no.12
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• pp.9-22
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• 2022

Purpose: Establishing a competitive advantage in the aviation market is essential as the competition among domestic airlines intensifies. Therefore, this study examined the management strategies of both large domestic airlines and low-cost airlines. Research design, data, and methodology: This study classified domestic airlines into Full Service Airlines (FSA) and Low Cost Carriers (LCC), examined each airline's current status and characteristics, and conducted case analyses of FSA and LCC based on Porter's generic competitive strategy. Results: The analyses determined that LCC primarily implemented a cost-advantage strategy, and FSA implemented a differentiation strategy. However, as competition intensified, FSA pursued cost-advantage strategies while establishing LCC through subsidiaries. There are various specific cost reduction methods, including service simplicity, scalability, high utilization, low landing fees, low-cost unit, and point-to-point flight strategies. Conclusions: LCCs are focusing on cost advantage strategies that reduce costs; however, the FSA also runs special price events that are as good as LCCs and are comparable to LCCs on some routes. Furthermore, LCC has recently expanded its mid- and long-distance routes, making competition for long-distance routes with major airlines unavoidable.

• Archives of Craniofacial Surgery
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• v.22 no.3
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• pp.168-172
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• 2021

Posttraumatic pseudoaneurysm of the face is caused by blunt, penetrating, or surgical trauma. Although its incidence is low, pseudoaneurysm rupture can cause a life-threatening, massive hemorrhage. A 48-year-old man visited our emergency center due to a fall-down accident. Three-dimensional computed tomography (CT) showed a comminuted zygomaticomaxillary complex fracture of the left face. After open reduction and internal fixation, the surgical wound healed without any complications. However, the patient was readmitted 10 days after surgery due to pus-like discharge from the wound. Contrast-enhanced CT to find the abscess unexpectedly revealed a pseudoaneurysm in the left retromaxillary area. Massive oral bleeding occurred on the night of re-hospitalization and emergency surgery was done. The bleeding site was identified as a pseudo-aneurysmal rupture of the posterior superior alveolar artery in the retromaxillary area. Hemostasis was achieved by packing Vaseline gauze in the maxillary sinus using an endoscope. Delayed rupture and massive bleeding of posttraumatic retromaxillary pseudoaneurysm after a zygomaticomaxillary fracture is a low-probability, but high-impact event. Therefore, additional contrast-enhanced CT should be considered to evaluate the possibility of a posttraumatic pseudoaneurysm in cases of severe comminuted zygomaticomaxillary fracture.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.363-373
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• 2021

The present study seeks to investigate the degree of awareness that constitutes the audit gap expectations (AEG) to determine which audit responsibilities can be narrowed or even eliminated. The author had surveyed a sample comprising four groups including auditors, auditees, the financial community, and other interest groups. In this survey, 1400 questionnaires were sent to the respondents, and the total number of responses was 454. The collected data was processed using statistical software SPSS, version 22. The Chi-Square test was used to analyze the effect of professional differences on AEG. The results of this study indicate that AEG cannot be eliminated due to the occupational impact of each survey group (about 46%), but it can be narrowed down to 54%, including a reduction of 11% in the knowledge gap (lack of public knowledge), 13% in the reasonable expectations gap (unqualified audit quality), 30% in the deficient standards gap (limited auditing standards). These results could be attained by improving training, communicating, and adding more responsibilities. This is the first study that provides another method of measuring the contribution of the knowledge gap through professional differences and professional gaps that make up each of the AEG's components.

• East Asian Journal of Business Economics (EAJBE)
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• v.9 no.1
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• pp.27-39
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• 2021

Purpose - According to the actual change of the logistics concept, the outsourcing activities of companies are actively progressing, and this is proceeding to third-party logistics and fourth-party logistics. This change in logistics situation raises the need for an in-depth understanding of four-party logistics. Research design, data, and methodology - In this study, first of all, the theoretical aspects of changes in the logistics concept are identified, along with the outsourcing and third-party logistics. Finally, the concept of four-party logistics, the background of its introduction, and future prospects will be explored. Result - The meaning of physical distribution is now passing through the existing three-party logistics and entering the era of four-way logistics. In addition, cost reduction and improvement of customer service through advanced logistics strategy can be said to be the company's competitiveness. Through this study, it can be seen that the conceptual change of logistics and the introduction of four-party logistics are closely related to the survival of the company's deficit in the market. Conclusion - In modern society, logistical competitiveness is the competitiveness of a company, and logistical activities of a company can be achieved through the process of entering the four-party logistics from the existing third-party logistics based on outsourcing. Then more customer-oriented service can be provided.

• Particle and aerosol research
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• v.17 no.4
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• pp.107-114
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• 2021

In this study, the effect of the air purifier located in the living room on the reduction of PM_2.5 concentration in the living room and bedroom was investigated. Measurements were carried out in real-life for about 2 weeks in a Korean apartment building where a 3-person household had lived and the exclusive private area was 84.9 m². When the air purifier in the living room was operating, the change in PM_2.5 concentration was measured when the door to the bedroom connected to the living room was opened and closed. In the case of living with the bedroom door open, the average PM_2.5 concentrations in the living room and bedroom were almost the same. When living with the bedroom door closed, the average PM_2.5 in the living room was higher than in the bedroom. The ventilation and cooking effects in the living room mainly affected the PM_2.5 concentration in the living room. Only one air purifier in the living room was able to keep the PM_2.5 concentration in the living room and bedroom low.