• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.443-454
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• 2020

The JavaScript engine is a module that receives JavaScript code as input and processes it, among many functions that are loaded into web browsers and display web pages. Many fuzzing test studies have been conducted as vulnerabilities in JavaScript engines could threaten the system security of end-users running JavaScript through browsers. Some of them have increased fuzzing efficiency by guiding test coverage in JavaScript engines, but no coverage guided fuzzing of optimized, dynamically generated machine code was attempted. Optimized JavaScript codes are difficult to perform sufficient iterative testing through fuzzing due to the function of runtime guards to free the code in the event of exceptional control flow. To solve these problems, this paper proposes a method of performing fuzzing tests on optimized machine code by avoiding deoptimization. In addition, we propose a method to measure the coverage of runtime-guards by the dynamic binary instrumentation and to guide increment of runtime-guard coverage. In our experiment, our method has outperformed the existing method at two measures: runtime coverage and iteration by time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3544-3564
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• 2022

With the development of the NB-IoT (Narrow band Internet of Things) and smart cities, coupled with the emergence of smart smoke sensors, new requirements and issues have been introduced to study on the deployment of sensors in large spaces. Previous research mainly focuses on the optimization of wireless sensors in some monitoring environments, including three-dimensional terrain or underwater space. There are relatively few studies on the optimization deployment problem of smart smoke sensors, and leaving large spaces with obstacles such as libraries out of consideration. This paper mainly studies the deployment issue of smart smoke sensors in large spaces by considering the fire probability of fire areas and the obstacles in a monitoring area. To cope with the problems of coverage blind areas and coverage redundancy when sensors are deployed randomly in large spaces, we proposed an optimized deployment strategy of smart smoke sensors based on the PSO (Particle Swarm Optimization) algorithm. The deployment problem is transformed into a multi-objective optimization problem with many constraints of fire probability and barriers, while minimizing the deployment cost and maximizing the coverage accuracy. In this regard, we describe the structure model in large space and a coverage model firstly, then a mathematical model containing two objective functions is established. Finally, a deployment strategy based on PSO algorithm is designed, and the performance of the deployment strategy is verified by a number of simulation experiments. The obtained experimental and numerical results demonstrates that our proposed strategy can obtain better performance than uniform deployment strategies in terms of all the objectives concerned, further demonstrates the effectiveness of our strategy. Additionally, the strategy we proposed also provides theoretical guidance and a practical basis for fire emergency management and other departments to better deploy smart smoke sensors in a large space.

• Health Policy and Management
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• v.24 no.3
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• pp.205-218
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• 2014

Background: Most studies on the national health insurance benefit expansion policy have focused on policy tools or decision-making process. Hence there was not enough understanding on how policies are actually implemented within the specific policy context in Korea which has a national mandatory health insurance system with a dominant proportion of private providers. The main objectives of this study is to understand the implementation process of the benefit coverage expansion policy. Unlike other implementation studies, we tried to examine both the process of implementation and decision making and how they interact with each other. Methods: Interviews were conducted with the ex-members of the Health Insurance Policy Review Committee. Medical doctors who implement the policy at the 'street-level' were also interviewed. To figure out major variables and the degree of their influences, the data were analyzed with Winter's Policy Implementation Model which integrates the decision making and implementation phases. Results: As predicted by the Winter model, problems in the decision making phase, such as conflicts among the members of committee, lack of applicable causal theories application of highly symbolic activities, and limited attention of citizen to the issue are key variables that cause the 'implementation failure.' In the implementation phase, hospitals' own financial interests and practitioners' dependence on the hospitals' guidance were barriers to meeting the policy goals of providing a better coverage for patients. Patients, the target group, tend to prefer physicians who prescribe more treatment and medicine. To note, 'fixers' who can link and fill the gap between the decision-makers and implementers were not present. Conclusion: For achieving the policy goal of providing a better and more coverage to patients, the critical roles of medical providers as street-level implementers should be noted. Also decision making process of benefit package expansion policy should incorporate its influence on the implementation phase.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.2
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• pp.121-127
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• 2011

This paper presents an autonomous formation flight algorithm for micro aerial vehicles (MAVs) and its flight test results. Since MAVs have severe limits on the payload and flight time, formation of MAVs can help alleviate the mission load of each MAV by sharing the tasks or coverage areas. The proposed formation guidance law is designed using nonlinear dynamic inversion method based on 'Leader-Follower' formation geometric relationship. The sensing of other vehicles in a formation is achieved by sharing the vehicles' states using a high-speed radio data link. the designed formation law was simulated with flight data of MAV to verify its robustness against sensor noises. A series of test flights were performed to validate the proposed formation guidance law. The test result shows that the proposed formation flight algorithm with inter-communication is feasible and yields satisfactory results.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.176-176
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• 2023

The Tonle Sap is the richest and diverseness of freshwater ecosystem in Southeast Asia, receiving nurturing water flows from the Mekong and its immediate basin. In addition, the rapid development in the Tonle Sap Lake (TSL) Basin, and flood inundation may threaten the natural diversities and characteristics. The impacts of flood inundation in 11 sub-basins contributing to the Tonle Sap Lake were assessed using the Rainfall-Runoff-Inundation (RRI) model to quantify the potential magnitude and extent of the flooding. The RRI model is set up by using gauged rainfall data to simulate the information of river discharge and flood inundation of huge possible flood events. Moreover, two satellite precipitation products (SPPs), CHIRPS and GSMaP, within respectively spatial resolutions of 0.05° and 0.1°, are utilized as an input for the RRI model to simulate river discharge, flood depth, and flood extent for the great TSL Basin of Cambodia. This study used statistical indicators such as NSE, PBIAS, RSR, and R2 as crucial indices to evaluate the performance of the RRI model. Therefore, the findings of this study could provide promising guidance in hydrological modeling and the significant implications for flood risk management and disaster preparedness in the region.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.111-125
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• 2018

In this study, we evaluated the uniformity of deposition rate and particle size distributions of the variable rate application technique using the unmanned rotorcraft by measuring the spray pattern according to path location in the range of spraying flight. The coefficient of variation (CV) of the lateral coverage rate for the overlapped distribution with the spray swath of 3.6 m in both guidance and auto-pilot flight modes maintaining constant flight speed was about 30% and the CV of the coverage rate by the flight path location was extremely small. Therefore, it was assessed that the variable rate application technology compensating for the variation of ground speed was superior in terms of spray uniformity. In addition, the droplet size distributions in both volume median diameter(VMD) and number median diameter(NMD) were adequate for aerial application and uniform in terms of lateral distribution. Thereafter, we intend to contribute to a precise application on small-scaled fields using the unmanned agricultural rotorcraft by the variable rate application.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2335-2337
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• 2001

In this paper, we address a new complete coverage navigation algorithm and guidance methodology for the cleaning robot. The proposed algorithm is based on the grid map. Six templates, excluding a Back-Trace(BT) template are used as the local navigation method. The effectiveness of the algorithm proposed in this paper is thoroughly demonstrated through simulations and the evaluation of parameters for the path execution.

• Electronics and Telecommunications Trends
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• v.34 no.6
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• pp.1-16
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• 2019

The paper presents five strategic opinions for promoting the fourth industry revolution through the supply of 5G additional frequency. The assessments are on the basis of 5G frequency utilization technologies and services, with reference to 3GPP 5G New Radio standards, after investigating the domestic 1G, 2G, 3G, 4G, and 5G mobile communication services as well as the use of mobile radio frequency and spectrum. The presented opinions contain the frequency supply of contiguous-wide bandwidth channels, harmonized frequency supply between licensed and unlicensed spectrum, the existing 4G frequency recycle for increasing 5G coverage and capacity, balance frequency supply in the multi-band for 5G services, and the development of 5G vertical frequency for industry. The aim is that the presented five strategic opinions can offer guidance for the upcoming plan of domestic 5G additional frequency supply.

• East Asian mathematical journal
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• v.37 no.5
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• pp.599-612
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• 2021

In China, Weibo is one of the social platforms with more users. It has the characteristics of fast information transmission and wide coverage. People can comment on a certain event on Weibo to express their emotions and attitudes. Judging the emotional tendency of users' comments is not only beneficial to the monitoring of the management department, but also has very high application value for rumor suppression, public opinion guidance, and marketing. This paper proposes a two-input Adaboost model based on TextCNN and BiLSTM. Use the TextCNN model that can perform local feature extraction and the BiLSTM model that can perform global feature extraction to process comment data in parallel. Finally, the classification results of the two models are fused through the improved Adaboost algorithm to improve the accuracy of text classification.

• Journal of the Korean Society of School Health
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• v.10 no.2
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• pp.137-156
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• 1997

Most education materials on sexuality developed in the past 10 years have not been thoroughly evaluated. This study provides results from a content analysis of 5 education materials for primary, middle and high school student. The results of this study were as follows: The Analysis Framework was developed to measure content in the education materials. It was organized into six domains. They are "Human Development", "Relationship", "Personal Skills", "Sexual Behavior", "Sexual Health", "Society and Culture". Each was associated topics and age appropriate developmental guides. The standard for analysis was the developmental guide suggested by the analysis framework. Each education material was assessed for developemtal guidance and its appropriateness for primary, middle and high school students. The total number of "being" responses to each developmental guidance equaled the score the material earned. These scores then were judged as to how well each education materials was comprehensive. 3 of 5 education materials were addressed as less than half the developmental guidline. Certain education materials were less comprehensive than others. I want to know 'Sexuality' covered the fewest developmental guidliness (34.6%). Interstingly, certain domains received much more coverage across all education materials than others. Most education materials provided instruction concerning "Human Development" (62.6%), "Sexual Health" (61.0%). However, topics such as "Personal Skills" (16.2%), "Relationship" (44.1%), "Sexual Behavior" (46.8%), "Society and Culture" (48.6%) were rarely addressed. Three topic, "negotiation", "sexual fantasy", "sexual dysfunction", were never addressed by most of the materials. Because several of the education material contained gender and sexual orientation biases. Certain topics such as "sexual identity and orientation" and "Gender role" were not adequately addressed by most of the material. Unfortunately, the overall findings of this study revealed that most of the education materials were considered insufficient for students. Because this study focused on whether or not the education materials addressed the developmental guidlines, further research is recommended to evaluate and addressed each developmental guidline.