Queue-affectance-based scheduling in multi-hop wireless networks under SINR interference constraints

Most distributed wireless scheduling schemes that are provably efficient have been developed under the protocol model, which describes interference constraints in a binary form. However, the oversimplified interference model imposes fundamental limitations on the performance in practice. The signal-to-interference-plus-noise-ratio (SINR) based interference model is more accurate and realistic accounting for the cumulative nature of the interference signals, but its complex structure makes the design of scheduling schemes much more challenging. In this paper, we focus on the scheduling performance under the SINR model and develop random access scheduling schemes that are amenable to implement in a distributed fashion with only local information. We analytically show that they are provably efficient under the SINR model, and through simulations demonstrate that they empirically perform better than the theoretical performance bound

Does Information from the Higher Education and R&D Institutes Improve the Innovation Efficiency of Logistic Firms?

The efficiency of logistics innovation is a challenging task for logistics companies competing in rapid environmental changes. It is also essentially crucial for logistics companies to understand the importance of various sources of information to achieve innovation efficiently. Thus, this study measured the innovation efficiency of 72 logistics firms in South Korea by using ‘the sales’ as an output factor, and ‘the number of employees’ and ‘the innovative activity cost’ as an input factor. In particular, this study tested whether the distribution of measured innovation efficiency value differs in terms of the degree of consideration of higher education institutes and research and development (R & D) institutes as sources of information. To investigate the innovation efficiency of Korean logistics firms, we used a combined method of the input-oriented data envelopment analysis (DEA) with constant return to scale and Kruskal Wallis one-way ANOVA (analysis of variance) techniques. The findings in the study suggest that the logistics firms in Korea tend not to seriously consider higher education institutes and R & D institutes as crucial sources of information for achieving their logistics innovation. However, the results show that the innovation efficiency of logistics firms may be low if they completely exclude or do not consider the information sources for their innovation activities. Keywords: Source of Information, Logistic firms, Innovation efficiency nonparametric statistics, Higher education institutes, R&D institute

Does Reduction of Material and Energy Consumption Affect to Innovation Efficiency? The Case of Manufacturing Industry in South Korea

“Reduction of material and energy consumption„ (RMEC) exists as a major objective of innovation and it is proved to affect positively to innovation performance from previous literature. Though innovation should be measured in efficiency rather than performance itself, however, the relationship between material and energy reduction on innovation efficiency is still unanswered. In this paper, we analyzed the effect of RMEC on innovation efficiency considering both innovation inputs and outputs. We utilized data of 388 manufacturing enterprises in Korea, and performed data envelopment analysis (DEA) and tobit regression analysis. According to the result, firms show difference by industry type in terms of innovation efficiency and RMEC. Moreover, the effect of RMEC on innovation efficiency turned out to be negative. The result indicates a possibility that input used for innovation might overweigh the output yielded when firms pursue innovation for the RMEC

Exploiting TTP Co-Occurrence via GloVe-Based Embedding With MITRE ATT&CK Framework

The digital transformation of various systems has brought great convenience to our daily lives, but it has also increased the level of cyberattacks. As the number of cyberattacks has increased, so has the number of reports analyzing them, MITRE publishes the ATT&CK Matrix which analyzes the tactics and techniques of attacks based on real-world examples. As the flow of attacks has become more understandable through TTP information, researchers have been using it with deep learning models to detect or predict attacks, which makes embedding essential to train the model. In previous studies on embedding TTPs, embedding is limited to simple statistical methods such as one-hot encoding and TF-IDF. Such methods do not consider the order of TTPs and the conceptual similarity between TTPs, therefore do not capture the rich information that TTPs contain. In this paper, we propose embedding TTP with GloVe, a method using a co-occurrence matrix. To properly evaluate the semantic embedding performance of TTP, we also propose a measurement called Tactic Match Rate (TMR). In the experimental results, 8 out of 14 tactics showed a TMR of more than 0.5. Especially the “TA0007 (Discovery)” tactic showed the highest TMR of 0.87. Through correlation analysis, the experimental result shows that the reason for the different embedding performances of the tactic is affected by the frequency of the technique in the same tactic, with at most a 0.96 score. We also experimentally demonstrated that the neutrality of TTP affects learning performance

Downlink Capacity of Super Wi-Fi Coexisting with Conventional Wi-Fi

Super Wi-Fi is a Wi-Fi like service over TV white spaces (TVWS) based on the dynamic spectrum access (DSA) technology. Although Super Wi-Fi is expected to achieve larger coverage than conventional Wi-Fi thanks to the superior propagation characteristics of TVWS, it suffers from smaller bandwidth than Wi-Fi (6-8 MHz versus 20 MHz) which degrades network capacity. Therefore, it is common belief that the two Wi-Fi technologies may target different applications such as Super Wi-Fi for coverage and Wi-Fi for speed. However, there is a lack of studies that rigorously analyzes and compares the performance of Super Wi-Fi and Wi-Fi to confirm such belief. To fill the gap, this paper performs a thorough analysis on the capacity of Super Wi-Fi under the scenario that a Super Wi-Fi access point (AP) coexists with a Wi-Fi AP. Comparing the downlink capacity of Super Wi-Fi and Wi-Fi reveals that Super Wi-Fi can outperform Wi-Fi at the outskirts of the Wi-Fi's coverage and Super Wi-Fi gets more beneficial when channel bonding is employed. In addition, the maximal coverage radius of Super Wi-Fi is derived with which Super Wi-Fi can achieve better average capacity than a network of densely-deployed Wi-Fi APs, where the maximal radius is up to 3.2 times larger than the coverage radius of Wi-Fi

The Perception of Occupational Safety and Health (OSH) Regulation and Innovation Efficiency in the Construction Industry: Evidence from South Korea

Due to safety issues in the construction industry, interest in research on occupational safety and health (OSH) regulations remains high. Previous studies indicated that OSH regulations not only affect performance in and of themselves, but also indirectly by increasing awareness of such regulations. Studies also demonstrated that OSH regulation can affect innovation and corporate safety. However, the effect of OSH regulation on innovation remains unclear, as the relationship between the perception of OSH regulation and innovation is not fully understood. This study measures the innovation efficiency of companies in the Korean construction industry using data envelopment analysis (DEA), and investigates the relationship between innovation efficiency and companies’ perceptions of OSH regulations. Results indicate that companies that positively recognize OSH regulations tend to be more innovative than those that do not. This study also validates differences in innovation efficiency depending on the perception of OSH regulations by bootstrap DEA. The results of this study suggest appropriate strategies to promote innovation in the construction industry from the perspectives of both government and practitioners in firms

Development of Wheel Pressure Control Algorithm for Electronic Stability Control (ESC) System of Commercial Trucks

This paper presents a wheel cylinder pressure control algorithm for application to the vehicle electronic stability control (ESC) systems for commercial trucks. An ESC system is an active system that improves the driving stability by distributing the appropriate braking pressure to each wheel, which is an essential system for safe driving. It is important that the ESC system, through proper braking pressure supply, delivers the correct pressure under control. However, to reduce the cost involved, commercial trucks use a solenoid valve of the on/off-type, rather than a proportional valve that has good pressure control capability. The performance of a proposed wheel pressure control system based on an on/off solenoid valve control was verified by means of experiments conducted using the wheel pressure control algorithm presented in this paper

Product and service innovation: Comparison between performance and efficiency

With the increasing importance of services in the manufacturing industry, manufacturers have been providing customers with packages that combine products and services. Such a product–service combination trend is often referred to as “servitization” and/or “product–service system,” and its impact on firm performance has been studied over decades. Although firms can improve their performance through service and product innovation, uncertainty in services may cause them to experience potential risks. Notwithstanding the risk associated with undertaking both product and service innovation together vis-à-vis the increase in resource and effort utilization, several studies have focused on performance itself without considering the change in inputs. Thus, this study measures innovation efficiency, which represents the ratio of innovation outputs to inputs, and verifies the difference in innovation efficiency among three different innovation types: 1) both product and service innovation, 2) product innovation only, and 3) service innovation only. The differences in innovation performance, which is measured by the sales of innovative products and utilized as an output factor in estimating efficiency, are also verified to compare the results with the difference in innovation efficiency by innovation type, and the changes in inputs are inferred. This study demonstrates that firms performing both product and service innovation tend to achieve higher innovation performance than others, albeit lower innovation efficiency. Based on the results, this study suggests an appropriate innovation strategy for firm managers, depending on firms’ innovation objectives and input availability

What Is the Right Innovation Type for Your Industry? Evidence from Chemical Firms in Korea

The literature has two different perspectives on which innovation types should be implemented to achieve innovation performance; some argue that they should pursue process-oriented innovation, while others maintain that both product- and process-oriented innovation should be performed. Though innovation efficiency should be measured, which takes both input and output variables into account, the research so far has been measured only with the performance of the innovation. Accordingly, this study identifies which innovation type is the most advantageous in terms of innovation efficiency for the chemical firms. We use data of 64 Korean chemical companies from a 2016 Korean innovation survey and perform data envelopment analysis to calculate innovation efficiency. Kruskal–Wallis one-way ANOVA and bootstrap DEA were also conducted to compare the difference of innovation efficiency among groups, depending on which innovation types are oriented. The result shows that focusing on process innovation rather than both product and process innovation is more appropriate to achieve higher innovation efficiency, and pursuing process innovation rather than product innovation tends to achieve a higher level of innovation efficiency in the Korean chemical industry