• International Journal of Computer Science & Network Security
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• v.23 no.9
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• pp.141-149
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• 2023

Repacked mobile apps constitute about 78% of all malware of Android, and it greatly affects the technical ecosystem of Android. Although many methods exist for repacked app detection, most of them suffer from performance issues. In this manuscript, a novel method using the Constant Key Point Selection and Limited Binary Pattern (CKPS: LBP) Feature extraction-based Hashing is proposed for the identification of repacked android applications through the visual similarity, which is a notable feature of repacked applications. The results from the experiment prove that the proposed method can effectively detect the apps that are similar visually even that are even under the double fold content manipulations. From the experimental analysis, it proved that the proposed CKPS: LBP method has a better efficiency of detecting 1354 similar applications from a repository of 95124 applications and also the computational time was 0.91 seconds within which a user could get the decision of whether the app repacked. The overall efficiency of the proposed algorithm is 41% greater than the average of other methods, and the time complexity is found to have been reduced by 31%. The collision probability of the Hashes was 41% better than the average value of the other state of the art methods.

• The Journal of Internal Korean Medicine
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• v.41 no.6
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• pp.984-992
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• 2020

Objectives: This survey research was conducted to evaluate real-time non-face-to-face education in clinical Korean medicine conducted during the COVID-19 outbreak. Methods: This study was conducted with all 3rd and 4th grade students of the Department of Korean Medicine, Gachon University. The Korean Internal Medicine (Pulmonary) lecture course was held from April 1st to July 1st, 2020 for one semester. The lectures were conducted through real-time non-face-to-face education using the Cisco Webex program, and the lectures were mainly conducted by sharing a PowerPoint summarizing textbook. The questionnaire consisted of 3 parts and a total of 18 questions. The survey was conducted anonymously to ensure the confidentiality of all responses. Results: The overall score for real-time non-face-to-face education was 74.69±18.15 points. The efficiency of real-time non-face-to-face education was 2.12±0.78 points, and opinions on the expansion of future use were 2.08±0.91 points and were generally positive. The ratio of non-face-to-face education and face-to-face education in future clinical Korean medicine theory lectures was about 63:27, with a higher proportion of non-face-to-face education. Conclusions: Promoting clinical Korean medicine as a non-face-to-face education has generally been positively evaluated in terms of efficiency and overall, and its use should be expanded in the future. In particular, it will be necessary to use non-face-to-face education in the theory classes of clinical Korean medicine. However, technical problems involving internet, video, equipment, and communication tools will need to be improved in the future.

• Korea Trade Review
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• v.42 no.5
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• pp.137-159
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• 2017

This study divides manufacturing in 18 countries including Korea, China, Japan and OECD countries into 11 areas and estimates and compares the technological efficiency of each industry. The traditional view of productivity is to increase production capacity through technological innovation or process innovation, but it is also influenced by the technological efficiency of production process. A Stochastic Frontier Production Model (SFM) is a representative method for estimating the technical efficiency of such production. First, as a result of estimating the production function by setting the output variable as total output or value-added, in both cases, the output increased significantly in all manufacturing sectors as inputs of labor, capital, and intermediate increased. On the other hand, R&D investment has a large impact on output in chemical, electronics, and machinery industries. Next, as a result of estimating the technological efficiency through the production function, when the total output is set as the output variable, the overall average of each sector is 0.8 or more, showing mostly high efficiency. However, when value-added was set, Japan had the highest level in most manufacturing sectors, while other countries were lower than the efficiency of the total output. Comparing the three countries of Korea, China and Japan, Japan showed the highest efficiency in most manufacturing sectors, and Korea was about half or one third of Japan and China was lower than Korea. However, in the food and electronics sectors, China is higher than Korea, indicating that China's production efficiency has greatly improved. As such, Korea is not able to narrow its gap with Japan relatively faster than China's rapid growth. Therefore, various policy supports are needed to promote technology development. In addition, in order to improve manufacturing productivity, it is necessary to shift to an economic structure that can raise technological efficiency as well as technology development.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.26-39
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• 2015

UHD (Ultra High Definition) has been developed and standardized over the past few years and considered as a key of the next generation broadcasting. Since major sporting events that attract many viewers have been good opportunities for applying and promoting new broadcasting technology, KBS (Korean Broadcasting System) has carried out live 4K terrestrial broadcasting of three big sports events in 2014, the KBL (Korean Basketball League) finals, the 2014 FIFA World Cup, and the 2014 Incheon Asian Games. Especially, 4K UHD live coverage of the KBL finals was the world's first live 4K terrestrial broadcasting, and people could enjoy the World Cup and the Asian Games with UHDTV at home. In this paper, the overall live production and data transmission of the sporting events is described, including on-location live production, live HEVC (High Efficiency Video Coding) encoding, SFN (Single Frequency Network) transmission, as well as experimental IP transmission of uncompressed 4K video via KREONET, a national R&D network run by KISTI (Korea Institute of Science and Technology Information).

• Journal of Korea Port Economic Association
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• v.37 no.1
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• pp.19-30
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• 2021

The 21st Century Maritime Silk Road (MSR) is an important part of Belt and Road Initiative(BRI). As an economic and trade corridor for dozens of countries in Asia, Europe and Africa, and the port as an important link node, the efficiency of port operation directly affects the implementation of BRI's strategy. On the basis of combining BRI and related evaluation methods of port efficiency, this paper uses DEA-BCC model to select port production berth number and production berth length as input index container throughput and cargo throughput as output index to analyze the port efficiency of 14 ports in China. The results show that: (1) The overall efficiency level of the ports along the MSR is relatively low. Most of the ports have not reached the DEA efficiency and there are different degrees of problems in scale investment and technological improvement. However, this situation is accompanied by the implementation of China's maritime cooperation strategy and becoming better year by year. (2) The low operating efficiency of ports along China's MSR is mainly due to the lack of coordination between scale efficiency and technical efficiency, which is caused by insufficient scale investment in the port itself, weak economic linkage between the hinterland and the port, (3) Whether a port has a strong comprehensive strength does not entirely depend on the cargo throughput or scale but also includes the port's operating efficiency.

• Journal of Korea Port Economic Association
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• v.30 no.2
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• pp.113-132
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• 2014

With the global warming phenomenon, the deep sea water area that fishing vessels can enter and operate is ever widening. For example, the Arctic Ocean recently has overall competitive advantages due to having many deep-sea fish stocks. The North Pacific region is a strategic coastal district, the closest access point of Arctic Ocean. For Korean fishing vessels which now operate in North Pacific region, and want to entry the Arctic Ocean, the analysis of technical efficiency is needed for preparing the better industry's future. This paper aims to analyze the relative efficiency, and select the low effective deep-sea fishing vessels in the North Pacific, and to suggest their desirables strategies. As a research methodology, Data Envelopment Analysis (DEA) and Malmquist Index are applied to 16 fishing vessels for the periods(2009 to 2013). To draw out the efficiency of targeted deep-sea fishing vessels, gross tons, horsepowers, and operating days are used as input variables while total catch stands for an output variable. As a result, CCR efficiency, BCC efficiency and scalability efficiency are measured to be 0.8405, 0.9484 and 0.8858 respectively for 5 years (2009 to 2013). In conclusion, 38% of total tons, 36% of horsepowers and 29% of operating days each fishing vessel should be reduced to keep their competitive powers.

• THE INDUSTRY AND TECHNOLOGY OF GAS
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• v.5 no.1 s.6
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• pp.39-47
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• 2002

With the expansion of natural gas demands in many countries, the necessity of LNG receiving terminals has been increased. The offshore LNG Floating Storage and Regasification Unit (FSRU) attracts attentions not only for a land based LNG receiving terminal alternative, but also for a feasible and economic solution. Nowadays, as the reliability of offshore oil and gas floating facilities and LNG carriers gains with proven worldwide operations, the FSRU can achieve a safety level that can be comparable to an onshore terminal. The design development related with safety features of the FSRU has been extensively carried out by oil and gas companies, shipyards, engineering companies, and equipment vendors, and has been successful so far in many fields. The construction of the FSRU can be achieved by integrating various technologies and experiences from many disciplines and many participating companies and vendors. In this paper, reviews on some of the important design features and design improvements on FSRU together with the practical construction aspects in cargo containment, vaporization system, ESD system, and operation modes, have been covered in comparison with actual LNG carrier, onshore receiving terminal, and FPSO systems. In order to materialize an FSRU project, the technical and economic justification has to be preceded. It is believed that once the safety and technical soundness is convinced, the FSRU can bring a higher project feasibility by reducing the overall construction time and cost. Through this study, an FSRU design readily applicable to an actual project has been developed by incorporating experiences gained from many marine and offshore projects. The wide use of proven standard technologies adopted in the series construction of LNG carriers and offshore FPSOs will bring the project efficiency and reliability.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.35-44
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• 2020

The purpose of this paper is to investigate various factors affecting the efficiency of China IC industry, reflecting the resource utilization and overall development level of China IC industry. In this paper, three input indicators (R&D Expenditure, Cash paid to and for employees, Total fixed assets) and two output indicators (Net profit, Sales revenue) were selected for 17 listed companies in the IC industry with operating profit of less than 1 billion yuan in 2018 and applied the technology efficiency theory and DEA analysis method to analyze the relative efficiency of the output base. The study found that one of the 17 companies analyzed was efficient, two were inefficient on an inadequate scale, and the rest were inefficient due to insufficient production technology, scale and management level. This study argues that enterprises should reduce resource input appropriately and strengthen scientific and technological innovation management to maximize resource utilization efficiency. Therefore, this study has important practical significance for improving the efficiency of IC enterprises. The Malmquist method will be used to study the total factor productivity of small and Medium-sized companies in IC industry.

• Journal of Digital Convergence
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• v.18 no.9
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• pp.81-91
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• 2020

The logistics industry is a basic and strategic industry that supports the development of national economy and society. The purpose of this paper is to evaluate the logistics efficiency of 22 cities in Guangxi and Yunnan provinces in China, and to grasp the problems and constraints and present policy proposals to promote the transformation and upgrading of the industrial structure in Guangxi and Yunnan provinces. In this paper, five input indexes and four output indexes were selected and the data from 2016 to 2018 were analyzed through DEA method. According to the analysis, the logistics efficiency of Guangxi and Yunnan provinces is not bad overall, but the development of each region is not balanced and the level of logistics efficiency is quite different. And it is found that each city needs to further improve the level of scale because the input and production structure of logistics resources is unreasonable. The limitation of this study is that it is difficult to generalize the analysis results because only the data over the past three years have been analyzed. It is necessary to comprehensively implement longitudinal and transverse analyses by extending the future analysis period over a long period of time.

• ETRI Journal
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• v.40 no.3
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• pp.355-365
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• 2018

The increase in data traffic calls for investment in mobile networks; however, the saturating revenue of mobile broadband and increasing capital expenditure are discouraging mobile operators from investing in next-generation mobile networks. Mobile network sharing is a viable solution for operators and regulators to resolve this dilemma. This research uses a difference-in-differences analysis of 33 operators (including 11 control operators) to empirically evaluate the cost reduction effect of mobile network sharing. The results indicate a reduction in overall operating expenditure and short-term capital expenditure by national roaming. This finding implies that future technology and standards development should focus on flexible network operation and maintenance, energy efficiency, and maximizing economies of scale in radio access networks. Furthermore, mobile network sharing will become more viable and relevant in a 5G network deployment as spectrum bands are likely to increase the total cost of ownership of mobile networks and technical enablers will facilitate network sharing.