This letter presents a low‐power single‐slope analog‐to‐digital converter (ADC) for column‐parallel architectures. A simple and effective design technique is proposed to solve the input‐dependent ...power consumption problem of the conventional single‐slope ADCs. A decision‐feedback loop is implemented in the second stage of the comparator. Based on the negative‐feedback path, which is activated after the signal decision of the comparator, the input‐dependent dynamic current path in the amplifier is disabled. Furthermore, an additional low‐power design technique is proposed to save the power consumption of the ADC by optimizing the offset cancelling auto‐zero period. With the combination of the proposed techniques, the power consumption of the single‐slope ADC can be effectively saved while suppressing the dynamic current.
Based on the negative‐feedback path, which is activated after the signal decision of the comparator, the input‐dependent dynamic current path in the amplifier is disabled. Furthermore, an additional low‐power design technique is proposed to save the power consumption of the analog‐to‐digital converter (ADC) by optimizing the offset cancelling auto‐zero period. With the combination of the proposed techniques, the power consumption of the single‐slope ADC can be effectively saved while suppressing the dynamic current.
Hair treatments containing vegetable oils protect the damaged hair by surface coating and by penetrating in hair thereby filling the gaps caused by oxidative damage. Vegetable oil is composed mostly ...of medium-chain or long-chain fatty acids which exist as triglycerides. Although there are literatures which deal with the penetration of specific natural oils into hair there is a lack of research which provide the empirical data that can be used to explain the penetration of larger population of vegetable oils. This research was aimed to examine whether the chain length of fatty acid affect the penetration of fatty acid and protection in hair and also to apply the results on explaining the protective effect of Medium-Chain Triglyceride oil (MCT oil) and Coconut oil. Nine different hair treatments were formulated with three medium-chain fatty acids (C8:0, C10:0, C12:0), three long-chain fatty acids (C14:0, C16:0, C18:0), MCT oil, Coconut oil, and a blank. Composition of fatty acids of hair was examined by the Gas chromatography mass spectrometry. Penetration of fatty acid in hair was examined by the UV–VIS spectrophotometry. Protection of damaged hair was examined by the differences in color, tensile strength, thickness, and the concentration of protein leak of 21-day vs. 0-day measurements. Results of t-test indicated that the penetration and the protection of the medium-chain fatty acid was significantly better than those of the long-chain fatty acid, and that MCT oil and coconut oil were not significantly different.
Cerium is a rare-earth metal commonly used as a dopant in various metal oxides to enhance their performances or provide optoelectronic properties. Cerium oxide (ceria) is particularly valuable owing ...to its unique properties and applications in various fields, such as biomedical research, photovoltaics, and industrial catalytic processes. This review focuses on the use of cerium and ceria doping in the synthesis of SiO2 and ZnO. Studies have shown that Ce-doped SiO2 thin films exhibit luminescence properties and proton shielding capabilities, and that Ce-doped ZnO has potential applications in gas sensors. In this review, we highlight the potential for controlling the luminescence and optical characteristics of these materials via cerium doping, opening up possibilities for various technological advancements and potential applications of cosmic ray shielding in space photovoltaics.
This presents an all-digital phase-locked loop (ADPLL) system using triple-stage phase-shifting (TSPS) for fast locking. At the first stage, a phase-pulling multiplexer linearly pulls the phase of a ...feedback signal until the phase offset between the feedback and reference signals becomes sufficiently small. Then, a toggling phase-shifting in the second stage achieves further reduction of the phase offset by delaying the feedback and reference signals. A subsequent adaptive target index-shifting stage then detects fine-locking in frequency and rapidly performs phase-locking to the present phase of the feedback signal instead of the initial target phase. This TSPS-ADPLL avoids frequency peaking by choosing oscillator control codes that generate frequencies below or near the target. Fabricated in a 28nm CMOS process, this ADPLL can lock within <inline-formula> <tex-math notation="LaTeX">1.0~\mu \text{s} </tex-math></inline-formula>, producing a 2.4GHz output clock without frequency peaking. It has an RMS jitter of 2.53ps and draws 2.89mW from a 1.0V supply.
The drone industry is one of the most important areas of the Fourth Industrial Revolution. In the drone industry, delivery systems using drones are now facing commercialization as they have undergone ...many experiments and discussions. The purpose of this study is to find the best route in a delivery system using a drone. In this study, we have developed the existing Vehicle Routing Problem (VRP) into a more realistic mathematical model considering the two differences between drones and vehicles; one is that power consumption varies with the weight of the loaded cargo and the other is that velocity is influenced by wind. This study also presents an Ant Colony System (ACS) algorithm to effectively solve VRP, a well-known NP-hard problem. The methodology of this study is quite successful and is expected to enable more realistic and effective routing decisions.
Metal Organic Frameworks as Tunable Linear Magnets Son, Kwanghyo; Kim, Rae Kyung; Kim, Suhwan ...
Physica status solidi. A, Applications and materials science,
June 2020, Volume:
217, Issue:
12
Journal Article
Peer reviewed
Due to the tunable magnetic exchange interactions between nearest neighbor moment carriers by exchange linker length or metal ions, metal–organic frameworks (MOFs) in general, and MOF‐74 in ...particular, have promising magnetic properties for novel industrial applications such as magnetic switchers, sensors, and multifunction devices in molecular spintronics. Hence, MOF‐74‐M M2(C8H2O6) (M = Fe, Co, Ni) possessing a 1D channel is prepared and experimentally examined to describe its diverse magnetic properties, depending on the metal cluster used. By exchanging the metal ion (Fe, Co, and Ni) in the metal cluster, the magnetic state of MOF‐74 is changed from ferromagnetic or antiferromagnetic to superparamagnetic. This phenomenon can be also confirmed by alternating current (AC)/direct current (DC) magnetic susceptibility and field‐dependent magnetization. Therefore, the intrinsic magnetic properties of MOF‐74‐M such as blocking temperature, Néel temperature, and interaction energy between metals in magnetic susceptibility tests can be elucidated. Moreover, the superparamagnetic behavior in this system is also observed in M–H curves and magnetic dynamics as single‐chain magnets. It is believed that MOF‐74‐M can be utilized for applications in which superconducting materials are required (e.g., memory‐storage devices).
The magnetic properties of selected metal–organic frameworks (MOFs) are assessed using alternating current (AC)/direct current (DC) magnetic susceptibility and field‐dependent magnetization. The magnetic state of the MOF‐74‐M (M = Fe, Co, Ni) studied can be changed from ferromagnetic or antiferromagnetic to superparamagnetic. These materials can be used for novel industrial applications in the field of molecular spintronics.
Reliability is a concept applied to systems used in various industrial sites and has been considered as an important measure in system design. The problem of determining the system structure to ...achieve optimal reliability under vari-ous constraints such as cost has been addressed and called Reliability Optimization Problems (ROP). But, the ROP is represented as a nonlinear binary integer programming problem and characterized as an NP-hard because it is the same as a knapsack problem with multiple choice constraints. So, various heuristic techniques have been developed to find relatively better solutions, rather than finding the best optimal solution. In this paper, the concept of cost-to-effectiveness is applied to the objective function to maximize reliability per unit cost setting the available budget to upper bound and the reliability at least to be satisfied to lower bound. Also, this study introduces an algorithm that guarantees global optimality of the ROP, and proves that it dramatically reduces the time required for finding optimal solution through GAMS experiments. KCI Citation Count: 0
The Korean Demilitarized Zone (DMZ) was established in 1953 during the cessation of the Korean War, which divided the Korean Peninsula into North and South Korea. The DMZ is a representative ...biodiversity resource because it limits human activities. The current status of faunal diversity in adjacent areas of the DMZ was investigated in five regions at 91 sites from 2015 to 2019. A total of 19,562 individuals were collected and identified, including 81 species, 19 families, and 11 orders. Zacco koreanus was the most abundant fish species (relative abundance of 21.9%), while other key species were Zacco platypus (18.2%), Rhynchocypris oxycephalus (5.2%), Rhynchocypris steindachneri (4.9%), and Pungtungia herzi (3.7%). Notably, twenty-nige endemic and seven Red Data Book species were recorded, and three exotic species, Carassius cuvieri, Micropterus salmoides, and Lepomis macrochirus were found at five sites. Human activities and disturbances were found at 34.0% of all sampling sites, and the highest disturbance factors were river dredging and agricultural use (seven sites), sewage (five sites), and fisheries and development (two sites). We recommend that the governments of South and North Korea collaboratively manage the DMZ to protect ecological diversity and maintain its status as a symbol of peace.
The performance comparison of target localization for active sonar and effective fusion algorithms for target localization of multistatic sonar is investigated. Active sonar can be categorized into ...monostatic, bistatic, and multistatic, depending on the number of receiver elements. Target localization performance depends on the system configuration. The target localization performance of the monostatic, bistatic, and multistatic sonar systems is compared assuming that each element can receive both range and azimuth information of the target. In addition, we propose the weighted least square (WLS) algorithm, which incorporates judicial weighting to the conventional least square (LS) method, and an efficient sensor arrangement rule for target localization in the multistatic sonar system. The representative experimental results demonstrate that the target localization performance of multistatic sonar configuration is superior in terms of root-mean-square error (RMSE), to monostatic sonar and bistatic sonar by 35.98% and 37.45%, respectively, while the proposed WLS algorithm showed an improvement of 2.27% compared with the LS method.
A triple-sampling <inline-formula> <tex-math notation="LaTeX">\Delta \Sigma </tex-math></inline-formula> ADC can replace the programmable gain amplifier commonly used in the readout circuit for a ...digital capacitive MEMS microphone. The input voltage can then be multiplied by subtracting a further half-period delayed differential input and using the feedback capacitor of the DAC as a sampling capacitor. This triple-sampling technique results in a readout circuit with noise performance comparable to recent designs, but with a reduced power requirement and increased sensitivity. A MEMS microphone incorporating this readout circuit, fabricated in a <inline-formula> <tex-math notation="LaTeX">0.18~\mu \text{m} </tex-math></inline-formula> CMOS process, had an area of 0.98mm 2 , achieved an A-weighted SNR of 62.1 dBA at 94 dBSPL with 520 <inline-formula> <tex-math notation="LaTeX">\mu \text{A} </tex-math></inline-formula> current consumption, to which triple-sampling was shown to contribute 4.5 dBA.
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