• International Journal of Computer Science & Network Security
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• v.24 no.1
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• pp.140-150
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• 2024

Database-as-a-Service is one of the prime services provided by Cloud Computing. It provides data storage and management services to individuals, enterprises and organizations on pay and uses basis. In which any enterprise or organization can outsource its databases to the Cloud Service Provider (CSP) and query the data whenever and wherever required through any devices connected to the internet. The advantage of this service is that enterprises or organizations can reduce the cost of establishing and maintaining infrastructure locally. However, there exist some database security, privacychallenges and query performance issues to access data, to overcome these issues, in our recent research, developed a database security model using a deterministic encryption scheme, which improved query execution performance and database security level.As this model is implemented using a deterministic encryption scheme, it may suffer from chosen plain text attack, to overcome this issue. In this paper, we proposed a new model for cloud database security using nondeterministic encryption, order preserving encryption, homomorphic encryptionand database distribution schemes, andour proposed model supports execution of queries with equality check, range condition and aggregate operations on encrypted cloud database without decryption. This model is more secure with optimal query execution performance.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.121-128
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• 2016

Social Media transformed the mass media based information traffic, and it has become a key resource for finding value in enterprises and public institutions. Particularly, in regards to disaster management, the necessity for public participation policy development through the use of social media is emphasized. National Disaster Management Research Institute developed the Social Big Board, which is a system that monitors social Big Data in real time for purposes of implementing social media disaster management. Social Big Board collects a daily average of 36 million tweets in Korean in real time and automatically filters disaster safety related tweets. The filtered tweets are then automatically categorized into 71 disaster safety types. This real time tweet monitoring system provides various information and insights based on the tweets, such as disaster issues, tweet frequency by region, original tweets, etc. The purpose of using this system is to take advantage of the potential benefits of social media in relations to disaster management. It is a first step towards disaster management that communicates with the people that allows us to hear the voice of the people concerning disaster issues and also understand their emotions at the same time. In this paper, Korean language text mining based Social Big Board will be briefly introduced, and disaster issue detection model, which is key algorithms, will be described. Disaster issues are divided into two categories: potential issues, which refers to abnormal signs prior to disaster events, and occurrence issues, which is a notification of disaster events. The detection models of these two categories are defined and the performance of the models are compared and evaluated.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.10
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• pp.213-220
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• 2020

The power consumption and performance of hardware-based mobile and IoT embedded systems that require high specifications are one of the important issues of these systems. In particular, the problem of excessive power consumption is because it causes a problem of increasing heat generation and shortening the life of the device. In addition, in the same environment, software also needs to perform stable operation in limited power and memory, thereby increasing power consumption of the device. In order to solve these issues, we propose a Low level power improvement via identifying performance dissipation. The proposed method identifies complex modules (especially Cyclomatic complexity, Coupling & Cohesion) through code visualization, and helps to simplify low power code patterning and performance code. Therefore, through this method, it is possible to optimize the quality of the code by reducing power consumption and improving performance.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.136-148
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• 2013

I would like to trace back periodic social trend by searching if regular performance might have reflected on social trend on its theme by analyzing theme trend of The National Dance Company of Korea, Dance Company of Seoul city, Dance Company of KyungKi-Do and to provide the meaningful results for further study by checking if the theme of dancing performance is in relation with social structure. To perform this research, I had studied on previous thesis and reference books. For example, I selected three groups, of The National Dance Company of Korea, Dance Company of Seoul city, Dance Company of KyungKi-Do, to research their theme of regular performance through checking previous thesis related to, performance material, news articles, pamphlets from beginning to present. How to analyze is being proceeded from foundation of dancing company to present according to Kim Byungseok's classification method, which was consistently used for searching theme trend from previous study as below; 1) Theme based on traditional conscious,2) Theme based on Literature, 3) Theme based on Historic issues, 4) Theme based on abstract, 5) Theme based on reality, 6)Theme based on social issues.

• Composites Research
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• v.37 no.2
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• pp.108-114
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• 2024

Due to the continuously increasing global demand for electricity, the demand for high-voltage submarine cables is also increasing. One of the issues that need to be addressed for submarine cables is the high production cost and expensive laying costs. Submarine cables exposed to the marine environment encounter external forces such as wave and current, leading to issues such as cable damage due to external factors or high maintenance costs in the event of an accident. Therefore, we are preparing for the uncertainty of the submarine environment through many protective materials and protective equipment. In this study, we examined the bending performance of piggyback clamps (PBC) and strap, which are representative protective equipment, in response to the submarine environment through analytical methods. To examine the structural performance of PBC, the bending performance were assessed under the maximum bending moment criterion of 15 kN·m for the flexible protection tube. As a result, it was confirmed that the structural performance regarding the bending moment of both PBC and straps was ensured.

• Journal of Construction Engineering and Project Management
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• v.6 no.3
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• pp.14-21
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• 2016

One of the major issues in the material-based or acceptance quality characteristics asphalt pavement Quality Assurance (QA) is that the method does not have rationality to link between the individual materials and the projected performance of the pavement. A new asphalt mix QA method has been recently developed under a national research project using the probabilistic Performance Related Specification (PRS). This advanced PRS QA methodology integrates the AASHTOWare Pavement ME Design$^{(R)}$ technology with the simple performance test concept that bridges the material characteristics with the pavement performance. This paper presents a case study of asphalt pavement performance using the developed PRS QA computer program, named Quality Related Specification Software (QRSS), with an actual pavement project, to demonstrate the developed PRS procedure and to assess the robustness of QRSS in terms of the rationality of the distress predictions. The results of this limited case study show that the new PRS QA method reasonably predicts the pavement performance, properly applied the probabilistic methods, and produced rational pay adjustment.

• Journal of Information Technology Applications and Management
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• v.21 no.2
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• pp.99-126
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• 2014

Tourism industry increasingly rely on information technology (IT) to improve the task performance. Many studies suggested that the evidence of IT showed not only task performance improvement but also organizational performance. Drawing from the resource-based view, technology and task fitness, and marketing orientation theories, this study proposes that IT use influences directly the task performance and proved the effectiveness of IT in the organizations of tourism industry. Further, the innovativeness, resources, and marketing orientation are identified as main determinants of IT use. The use of IT can serve as a catalyst in improving task performance for organizations in tourism industry. Based on data collected from surveying people who work in the tourism industry, the present study shed light on these issues. The findings provide a new perspective of IT effectiveness in the tourism industry. Then, we discussed the theoretical and practical implications.

• International Journal of Highway Engineering
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• v.17 no.2
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• pp.89-98
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• 2015

PURPOSES : The objective of this study is to evaluate the performance properties of chip seals and fog seals with polymer-modified emulsions. METHODS : The performance of chip seals and fog seals was evaluated on the basis of common issues in surface treatments. Granite aggregate and four types of asphalt emulsions (one of the unmodified and three of the modified emulsions) were used considering the usage in field. A Vialit test was performed to determine the aggregate retention, and the MMLS3 (Third Scale Model Mobile Load Simulator) test was conducted to determine the aggregate retention, bleeding, and rutting. In addition, the fog seal specimens were tested by the BPT (British Pendulum Test) to evaluate skid resistance. RESULTS AND CONCLUSIONS : Overall, the polymer-modified emulsions (PMEs) showed better aggregate retention and bleeding resistance for both chip seals and fog seals. When comparing the performance of the PMEs, the difference was not considerable. In addition, PMEs present significantly better rutting resistance than unmodified emulsions. For skid resistance, if the recommended mix design is applied, the specimens do not cause issues with skid resistance. Although all of the fog seal specimens were over the criteria for skid resistance, the specimen fabricated by the high emulsion application rate (EAR) of the unmodified emulsion was nearly equivalent to the skid value criteria. Therefore, the use of an unmodified emulsion with a high EAR should be carefully applied in the field.

• Journal of Environmental Science International
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• v.27 no.2
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• pp.75-81
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• 2018

At present research on mining backfill materials is being carried out to prevent ground subsidence and breaking by underground cavern of exhausted mines. However, backfill materials can cause secondary environmental issues such as ground pollution. To solve these issues, liner and cover materials are constructed before backfill materials constructed, to inhibit toxic substances form moving to the surroundings. Liner and cover materials, however, should have an accelerating performance after construction and when the accelerating performance is degraded, the work efficiency can be lowered, and the construction cost can be increased, by many rebound content. Therefore, this study develops mining liner and cover materials, and evaluates their accelerating performance and physical properties of liner and cover materials by types and content of accelerating agent. In case of aluminate accelerating agent, it is mixed with more than 5% of liner and cover materials(binder/ratio); thus an accelerating performance satisfying Korean Industrial Standards(KS) occurs, and in case of alkali-free accelerating agent, when it is mixed with more than 7%(binder/ratio), accelerating performance satisfying KS occurs. The more the accelerating agent capacity increases, the more compressive strength decreases. In addition, it is confirmed that compressive strength of aluminate accelerating agent is more degraded than compressive strength of the alkali-free accelerating agent. It is also confirmed that drying shrinkage stability of the alkali-free accelerating agent is better than the drying shrinkage stability of the aluminate accelerating agent.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.110-113
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• 1998

An analysis of the relationship between a linear amplifier chain and an analog-to-digital converter(ADC) in a digital microwave widevand receiver, with respect to sensitivity and dynamic range issues, is presented. The effects of gain, third-order intermodulation products and ADC characteristics on the performance of the receiver are illustrated and design criteria for the linear amplifier chain given a specified ADC are developed. A computer program is used to calculate theretical receiver performance based on gain and third-order intermodulation product selections. Simulated results are also presented and compared with theoretical values.