33 research outputs found
A Study on the Actuator Efficiency Behavior of Safety-Related Motor Operated Gate and Globe Valves
False Discovery Rate Controlling Procedures with BLOSUM62 substitution matrix and their application to HIV Data
Identifying significant sites in sequence data and analogous data is of
fundamental importance in many biological fields. Fisher's exact test is a
popular technique, however this approach to sparse count data is not
appropriate due to conservative decisions. Since count data in HIV data are
typically very sparse, it is crucial to use additional information to
statistical models to improve testing power. In order to develop new approaches
to incorporate biological information in the false discovery controlling
procedure, we propose two models: one based on the empirical Bayes model under
independence of amino acids and the other uses pairwise associations of amino
acids based on Markov random field with on the BLOSUM62 substitution matrix. We
apply the proposed methods to HIV data and identify significant sites
incorporating BLOSUM62 matrix while the traditional method based on Fisher's
test does not discover any site. These newly developed methods have the
potential to handle many biological problems in the studies of vaccine and drug
trials and phenotype studies
A Novel Mitigation Method for Noise-Induced Temperature Error in CPU Thermal Control
It has been reported that in the thermal control of real-time computing systems, zero-mean thermal sensor noise can induce a significant steady-state error between the target and actual temperatures of a CPU. Unlike the usual case of zero-mean sensor noise resulting in zero-mean temperature fluctuations around the target value, this noise-induced temperature error manifests in the form of a bias, i.e., the mean of the error is not zero. Existing work has analyzed the main cause of this error and produced a solution, known as TCUB-VS. However, this existing solution has a few drawbacks: the transient response is sluggish, and the exact value of the noise standard deviation is necessary in the design stage. In this paper, we propose a novel method of avoiding noise-induced temperature error while overcoming the limitations of the existing work. The proposed method uses an estimated CPU temperature for the part of the controller that is sensitive to noise while using actual measurements for the other part of the controller. In this way, our proposed method eliminates noise-induced temperature error and overcomes the drawbacks of the existing work. To show the efficacy of our proposed method, theoretical results are obtained using a stochastic averaging approach, and experimental results are presented along with simulations.1
HIGH CROSSOVER RATE1 encodes PROTEIN PHOSPHATASE X1 and restricts meiotic crossovers in Arabidopsis.
Meiotic crossovers are tightly restricted in most eukaryotes, despite an excess of initiating DNA double-strand breaks. The majority of plant crossovers are dependent on class I interfering repair, with a minority formed via the class II pathway. Class II repair is limited by anti-recombination pathways; however, similar pathways repressing class I crossovers have not been identified. Here, we performed a forward genetic screen in Arabidopsis using fluorescent crossover reporters to identify mutants with increased or decreased recombination frequency. We identified HIGH CROSSOVER RATE1 (HCR1) as repressing crossovers and encoding PROTEIN PHOSPHATASE X1. Genome-wide analysis showed that hcr1 crossovers are increased in the distal chromosome arms. MLH1 foci significantly increase in hcr1 and crossover interference decreases, demonstrating an effect on class I repair. Consistently, yeast two-hybrid and in planta assays show interaction between HCR1 and class I proteins, including HEI10, PTD, MSH5 and MLH1. We propose that HCR1 plays a major role in opposition to pro-recombination kinases to restrict crossovers in Arabidopsis.Marie Curie International Training Network COMREC
European Research Council (ERC)
National Research Foundation of Korea
Suh Kyungbae Foundatio
사이버물리시스템을 위한 네트워크와 제어 동시 설계
Cyber-Physical System (CPS), which is used in various fields, has received increasing attention. Since the advent of Industry 4.0, CPS has been actively studied in fields such as smart factories and vehicle networks. CPS is tight integration of cyber space and physical space through networking. Therefore, the design of a network that connects cyber space and physical space takes a large portion in the importance of CPS research. As CPS can be expressed in various types of systems, it is necessary to design various networks accordingly. This dissertation focuses on the wireless networked control system among CPS. However, there are various types of wireless networked control system, and since the network and physical systems in wireless network control system are mutually interacted, a network and control co-design is required, not network design. In this dissertation, we propose the network and control co-design of CPS that considers the following three situations: (i) wireless channel uncertainty, (ii) heterogeneous sampling rates, and (iii) hierarchical networked control system.Y1 Introduction 1
1.1 Background and Problems Addressed 1
1.2 Outline of Dissertation 2
2 Networked Control Systems for Cyber-Physical Systems 5
3 Resilient Architecture for Network and Control Co-Design under Wireless Channel Uncertainty 7
3.1 Introduction 7
3.2 Motivation: What Happens to Control Performance under Wireless Channel Uncertainty? 9
3.3 Problem Formulation 11
3.3.1 Conventional Network and Control Co-Design 11
3.3.2 Network and Control Co-Design with Rate Adaptation 15
3.4 W-Simplex: Resilient Architecture for Network and Control Co-Design 16
3.4.1 Wireless-Simplex (W-Simplex): Network and Control Co-Design against Wireless Channel Uncertainty 16
3.4.2 Control Cost 18
3.4.3 Network Delay Model 23
3.4.4 Network Performance Objective 28
3.5 Performance Evaluation 28
3.5.1 Simulation Setup 28
3.5.2 Control Performance under Uncertain Wireless Channel 30
3.6 Related Work 34
3.7 Conclusion 37
4 Sampling Rate Optimization for IEEE 802.11 Wireless Control Systems 41
4.1 Introduction 41
4.2 Related Work 43
4.3 Problem formulation 45
4.3.1 System Model 45
4.3.2 Network and Control Co-Design 47
4.3.3 Convex Relaxation 50
4.4 Performance Evaluation 54
4.4.1 Testbed 54
4.4.2 Simulation Study 56
4.4.3 Experiments 60
4.5 Conclusions and Future Work 63
5 Network and Control Co-Design for Large-Scale Cyber-Physical Systems 65
5.1 Introduction 65
5.2 Problem formulation 66
5.2.1 System description 66
5.2.2 System model 68
5.2.3 Network and Control Co-Design 69
5.3 Validation Experiments 75
5.3.1 Testbed 75
5.3.2 Local Network 78
5.4 Conclusions and Future Work 83
6 Conclusions of Dissertation 93
국문초록 102DoctordCollectio
Correlation of EDLC Capacitance with Physical Properties of Polyethylene Terephthalate Added Pitch-Based Activated Carbon
The electric double-layer capacitor (EDLC) has attracted attention by using activated carbon (AC) as an active electrode material with a high power density and high cost-efficiency in industrial applications. The EDLC has been actively developed over the past decade to improve the power density and capacitance. Extensive studies on EDLCs have been conducted to investigate the relation of EDLC capacitance to the physical properties of AC, such as the specific surface area, pore type and size, and electrical conductivity. In this study, EDLC was fabricated with AC, and its capacitance was evaluated with the physical properties of AC. The AC was prepared using petroleum-based pitch synthesized using pyrolysis fuel oil (PFO) with polyethylene terephthalate (PET). The AC based on PFO and PET (PPAC) exhibited high specific surface area and low micropore fraction compared to the PFO-based AC without PET addition (PAC). Furthermore, the reduction of the EDLC capacitance of PPAC was smaller than that of PAC, as the scan rate was increased from 5 to 100 mV s−1. It was determined that the minor reduction of capacitance with an increase in the scan rate resulted from the development of 4 nm-sized mesopores in PPAC. In addition, a comprehensive correlation of EDLC capacitance with various physical properties of ACs, such as specific surface area, pore characteristics, and electrical conductivity, was established. Finally, the optimal properties of AC were thereupon derived to improve the EDLC capacitance
The physical activity paradox in relation to work ability and health-related productivity loss in Korea
OBJECTIVES The physical activity paradox suggests that occupational physical activity (OPA), unlike leisure-time physical activity (LTPA), may detrimentally impact health. We explored the relationships of OPA and LTPA with work ability (WA) and health-related productivity loss (HRPL). METHODS This study included 5,501 workers in Korea who were recruited in 2021 through a web-based cross-sectional questionnaire. The questionnaire was utilized to quantify OPA and LTPA in metabolic equivalents, while WA and HRPL were also measured. Non-parametric regression, using a generalized additive model (GAM), was employed to visualize the relationships of LTPA and OPA with WA and HRPL. Mean differences in WA and HRPL, in relation to OPA and LTPA, were examined using linear regression models. These models were adjusted for covariates including sex, age, body mass index, education level, alcohol consumption, smoking history, insomnia, occupation, hours worked, and income. RESULTS The GAM and linear regression analyses revealed that higher LTPA corresponded with higher WA and lower HRPL. In contrast, as OPA increased, WA decreased and HRPL increased. However, within the group with high OPA, HRPL was not significantly lower in the high-LTPA subgroup relative to the low-LTPA subgroup (mean difference=1.92%, p=0.343). This pattern was especially pronounced among workers aged 60 years and older, with an increase in HRPL observed with increasing LTPA among the respondents with high OPA. CONCLUSIONS High LTPA levels were associated with elevated WA and diminished HRPL. In contrast, higher levels of OPA were associated with lower WA and higher HRPL
Resilient architecture for network and control co‐design under wireless channel uncertainty in cyber‐physical systems
In this paper, we propose a resilient architecture for network and control co-design, Wireless-Simplex (W-Simplex), which can ensure control performance by adaptively tuning the network and control parameters against wireless channel uncertainty in cyber-physical systems. To the best of our knowledge, there has been no research into resilient network and control co-design in response to the unreliable wireless channel. Our key observation is that rate adaptation may cause significant degradation in control performance or even system instability. This performance degradation is contrary to the intuition that rate adaptation provides a reliable link under wireless channel uncertainty. We explain the cause of this phenomenon and resolve the situation by proposing a resilient co-design algorithm in an optimization framework. Our simulation study with ns-2 shows the effectiveness of the proposed scheme to provide resilience of cyber-physical systems against wireless channel uncertainty. © 2018 John Wiley & Sons, Ltd.1