308 research outputs found
A bridge between robustness and simplicity: practical control design for complex systems
Automatic control design has been one of the major subjects in real-world system design/operation and is becoming much more significant today in accordance with increasing size, changing structure, uncertainties and complexity of artificial industry systems. A major challenge in a new environment is to integrate computing, communication and control into appropriate levels of real-world systems operation and control. In practice, many control systems usually track different control objectives such as stability, disturbance attenuation and reference tracking with considering practical constraints, simultaneously. At the moment in the industry applications, it is desirable to meet all specified goals using the controllers with simple structures. Since, practically these controllers are commonly designed based on experiences, classical and trial-and-error approaches, they are incapable of obtaining good dynamical performance to capture all design objectives and specifications for a wide range of operating conditions and various disturbances. It is significant to note that because of using simple structure, pertaining to the low-order control synthesis for dynamical systems in the presence of strong constraints and tight objectives are few and restrictive. Under such conditions, the synthesis process may not approach to a strictly feasible solution. Therefore, the most of robust and optimal approaches suggest complex state-feedback or high-order dynamic controllers. Moreover in the most of proposed approaches, a single performance criterion has been used to evaluate the robustness of resulted control systems. This research addresses three systematical, fast and flexible algorithms to design of low order or static output controllers for dynamical systems. The developed strategies attempt to invoke the strict conditions and bridge the gap between the power of optimal/robust control theory and industrial control design. To illustrate the effectiveness of the proposed control strategies, they have been applied to several complex systems in the electric industry
Finding Top-k Longest Palindromes in Substrings
Palindromes are strings that read the same forward and backward. Problems of
computing palindromic structures in strings have been studied for many years
with a motivation of their application to biology. The longest palindrome
problem is one of the most important and classical problems regarding
palindromic structures, that is, to compute the longest palindrome appearing in
a string of length . The problem can be solved in time by the
famous algorithm of Manacher [Journal of the ACM, 1975]. This paper generalizes
the longest palindrome problem to the problem of finding top- longest
palindromes in an arbitrary substring, including the input string itself.
The internal top- longest palindrome query is, given a substring
of and a positive integer as a query, to compute the top- longest
palindromes appearing in . This paper proposes a linear-size data
structure that can answer internal top- longest palindromes query in optimal
time. Also, given the input string , our data structure can be
constructed in time. For , the construction time is reduced
to
Mechanoresponsive Luminescent Molecular Assemblies: An Emerging Class of Materials
The possibility to change the molecular assembled structures of organic and organometallic materials through mechanical stimulation is emerging as a general and powerful concept for the design of functional materials. In particular, the photophysical properties such as photoluminescence color, quantum yield, and emission lifetime of organic and organometallic fluorophores can significantly depend on the molecular packing, enabling the development of molecular materials with mechanoresponsive luminescence characteristics. Indeed, an increasing number of studies have shown in recent years that mechanical force can be utilized to change the molecular arrangement, and thereby the optical response, of luminescent molecular assemblies of π-conjugated organic or organometallic molecules. Here, the development of such mechanoresponsive luminescent (MRL) molecular assemblies consisting of organic or organometallic molecules is reviewed and emerging trends in this research field are summarized. After a brief introduction of mechanoresponsive luminescence observed in molecular assemblies, the concept of “luminescent molecular domino” is introduced, before molecular materials that show turn-on/off of photoluminescence in response to mechanical stimulation are reviewed. Mechanically stimulated multicolor changes and water-soluble MRL materials are also highlighted and approaches that combine the concept of MRL molecular assemblies with other materials types are presented in the last part of this progress report
高速度工具鋼の疲労挙動と組織
取得学位:博士(工学),学位授与番号:博甲第1086号,学位授与年月日:平成21年3月23
Effects of a self-management program on antiemetic-induced constipation during chemotherapy among breast cancer patients: a randomized controlled clinical trial.
Research on patient-reported outcomes indicates that constipation is a common adverse effect of chemotherapy, and the use of 5-hydroxytryptamine (serotonin; 5HT3) receptor antagonists aggravates this condition. As cancer patients take multiple drugs as a part of their clinical management, a non-pharmacological self-management (SM) of constipation would be recommended. We aimed to evaluate the effectiveness of a SM program on antiemetic-induced constipation in cancer patients. Thirty patients with breast cancer, receiving 5HT3 receptor antagonists to prevent emesis during chemotherapy were randomly assigned to the intervention or control group. The SM program consisted of abdominal massage, abdominal muscle stretching, and education on proper defecation position. The intervention group started the program before the first chemotherapy cycle, whereas patients in the wait-list control group received the program on the day before their second chemotherapy cycle. The primary outcome was constipation severity, assessed by the constipation assessment scale (CAS, sum of eight components). The secondary outcome included each CAS component (0-2 points) and mood states. A self-reported assessment of satisfaction with the program was performed. The program produced a statistically and clinically significant alleviation of constipation severity (mean difference in CAS, -3.00; P = 0.02), decrease in the likelihood of a small volume of stool (P = 0.03), and decrease in depression and dejection (P = 0.02). With regards to program satisfaction, 43.6 and 26.4 % patients rated the program as excellent and good, respectively. Our SM program is effective for mitigating the symptoms of antiemetic-induced constipation during chemotherapy
Feasibility of using vessel-detection software for the endovascular treatment of visceral arterial bleeding
We aimed to investigate the feasibility of using vessel-detection software to identify damaged arteries during endovascular embolization in five patients with visceral arterial hemorrhages. We used a software program originally developed to detect tumor feeder vessels in liver tumor embolization with C-arm computed tomography datasets to detect the vessels responsible for the arterial hemorrhages in patients with splenic artery pseudoaneurysms (n=2), lower gastrointestinal bleeding (n=2), and bladder tumor bleeding (n=1). In all cases, the injured vessel was identified accurately on a three-dimensional vascular map at the optimal working angle with a relatively short mean processing time of 118 s (range, 107–136 s). The operating angiographers used this information to direct the catheter into the damaged artery without sequential angiographic runs. The software analysis was also used to plan coil delivery to the most appropriate site in the injured artery. The results suggest that the vessel-detection software for liver tumor embolization can also be used to detect damaged vessels and to plan treatment strategies in endovascular embolization of visceral arterial hemorrhage
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