共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
Vivek S Borkar 《Sadhana》1990,15(4-5):405-413
We consider the ergodic control of a Markov chain on a countable state space with a compact action space in presence of finitely
many (say,m) ergodic constraints. Under a condition on the cost functions that penalizes instability, the existence of an optimal stable
stationary strategy randomized at a maximum ofm states is established using convex analytic arguments. 相似文献
3.
利用单片微型计算机技术研制的一种行为功能测试仪,通过对交通警察及对照人群测试结果表明,该仪器测试的指标与世界卫生组织推荐的神经行为核心测试组合指标高度相关,可以用其测试结果及行为指数来评价人体行为功能。交通环境因素对交通警察信息感知、记忆能力有明显影响,且随着工龄增加、接触交通环境污染时间的增长,其信息感知、记忆能力影响愈大 相似文献
4.
5.
叙述了微机控制的低温恒温箱的硬件及软件实现,并对进一步提高系统的精度作了理论与实验探讨,得到了一组有用的试验曲线。 相似文献
6.
7.
Er. V. Kal’yanov 《Technical Physics Letters》2008,34(2):94-96
A chaotic autooscillatory system described by an equation with delayed argument is proposed, in which the oscillations are controlled by means of a chaotizing feedback algorithm. The results of numerical analysis of the proposed system are presented. 相似文献
8.
O. N. Romaniv V. V. Grytsyk A. S. Krys'kiv B. V. Kisil' L. K. Nevidomskii 《Materials Science》1991,26(6):701-706
Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 26, No. 6, pp. 100–105, November–December, 1990. 相似文献
9.
《Drug development and industrial pharmacy》2013,39(2-3):223-238
AbstractThe release of griseofulvin from griseofulvin: phospholipid coprecipitates has been studied as a function of 1) the fatty ester chain length of phosphatidylcholine, 2) the choice of solvent in forming coprecipitates, and 3) the ratio of phospholipid: cholesterol in the lipid component. Only coprecipitates containing 95%w/w and 80%w/w griseofulvin were examined. The release kinetics and total release after 60 min correlates with the phase transition temperatures of the various phosphatidylcholines. The addition of cholesterol diminishes the initial release rates but increases the total amount released after 60 min when the phospholipid:cholesterol mole ratio is greater than unity. The role of chloroform as an enhancer of the release process and the phospholipid as a solubilizer of griseofulvin is demonstrated. 相似文献
10.
M.B.M. De Koster 《IIE Transactions》1988,20(4):374-381
Production lines with integral control limits are studied in this paper. The behaviour of such lines can be shown to be approximated by that of flow lines with local buffers. The reduction of an integrally controlled line to a locally controlled one is computationally simple and accurate in the estimation of such performance measures as throughput, probabilities of buffers being full or empty and throughput time.
The advantage of such a reduction is that good techniques are available for estimating the performance of flow lines with local buffers only. Furthermore, a direct method is described for obtaining an estimate of the throughput of lines with integrally controlled buffers only. In the model used here, the product flow is continuous and the production units are unreliable. Both lifetimes and repair times of machines are distributed exponentially. 相似文献
The advantage of such a reduction is that good techniques are available for estimating the performance of flow lines with local buffers only. Furthermore, a direct method is described for obtaining an estimate of the throughput of lines with integrally controlled buffers only. In the model used here, the product flow is continuous and the production units are unreliable. Both lifetimes and repair times of machines are distributed exponentially. 相似文献
11.
12.
The release of griseofulvin from griseofulvin: phospholipid coprecipitates has been studied as a function of 1) the fatty ester chain length of phosphatidylcholine, 2) the choice of solvent in forming coprecipitates, and 3) the ratio of phospholipid: cholesterol in the lipid component. Only coprecipitates containing 95%w/w and 80%w/w griseofulvin were examined. The release kinetics and total release after 60 min correlates with the phase transition temperatures of the various phosphatidylcholines. The addition of cholesterol diminishes the initial release rates but increases the total amount released after 60 min when the phospholipid:cholesterol mole ratio is greater than unity. The role of chloroform as an enhancer of the release process and the phospholipid as a solubilizer of griseofulvin is demonstrated. 相似文献
13.
《Drug development and industrial pharmacy》2013,39(4):527-539
AbstractThe present investigation concerns the development of new dosage forms which, after oral administration, exert an active influence on their gastrointestinal transit. The dosage forms release excipients which aim to increase the lenght of time the drug spends in the absorbing section of the duodenum and small intestine. A delayed gastrointestinal transit is intended to achieve a more complete and longer lasting absorption of drugs with a limited duration of absorption. The present study examined whether, by incorporating triethanolamine myristate (165 mg) as an excipient in tablets containing riboflavine (20 mg) as an example of a drug with limited absorption, the gastrointestinal transit of riboflavine could be delayed and hence its absorption improved. Five subjects took part in the in vivo studies and a pH-telemetering device (Heidelberg capsule) was used to determine gastric residence time.The investigations showed that in 4 out of 5 subjects, the gastric residence time of the pH-telemetering capsule could be prolonged and the renal elimination of riboflavine increased The increase in renal elimination of riboflavine in the presence of triethanolamine myristate was statistically significant in the 4th urine collection period (0.05 > p> 0.0025). 相似文献
14.
15.
Ostrovidov S Annabi N Seidi A Ramalingam M Dehghani F Kaji H Khademhosseini A 《Analytical chemistry》2012,84(3):1302-1309
In this paper, we report a method to fabricate microengineered hydrogels that contain a concentration gradient of a drug for high-throughput analysis of cell-drug interactions. A microfluidic gradient generator was used to create a concentration gradient of okadaic acid (OA) as a model drug within poly(ethylene glycol) diacrylate hydrogels. These hydrogels were then incubated with MC3T3-E1 cell seeded glass slides to investigate the cell viability through the spatially controlled release of OA. The drug was released from the hydrogel in a gradient manner and induced a gradient of the cell viability. The drug concentration gradient containing hydrogels developed in this study have the potential to be used for drug discovery and diagnostics applications due to their ability to simultaneously test the effects of different concentrations of various chemicals. 相似文献
16.
Evone S. Ghali George H. Klinger Joseph B. Schwartz 《Drug development and industrial pharmacy》1989,15(9):1311-1328
Beads prepared by extruder/marumerizer technology were formulated with water soluble drugs, microcrystalline cellulose and several waxy materials. The waxes (10 to 50% by weight) were included in an effort to slow drug release. Subsequent thermal treatment of these beads was applied. Beads were processed to determine the effect of varying wax level, excipient, active drug, and effect of heat treatment. In-vitro drug release profiles were evaluated for the untreated and thermal treated beads. In general, the simple incorporation of wax into the granulation did not provide the desired controlled release dissolution profile. Thermal treatment of the finished beads, however, resulted in products which behaved in a different manner during dissolution testing and in general provided slower release. Drug release was found to vary with the type and level of wax, drug, excipient, and the thermal treatment. 相似文献
17.
《Drug development and industrial pharmacy》2013,39(9):1311-1328
AbstractBeads prepared by extruder/marumerizer technology were formulated with water soluble drugs, microcrystalline cellulose and several waxy materials. The waxes (10 to 50% by weight) were included in an effort to slow drug release. Subsequent thermal treatment of these beads was applied. Beads were processed to determine the effect of varying wax level, excipient, active drug, and effect of heat treatment. In-vitro drug release profiles were evaluated for the untreated and thermal treated beads. In general, the simple incorporation of wax into the granulation did not provide the desired controlled release dissolution profile. Thermal treatment of the finished beads, however, resulted in products which behaved in a different manner during dissolution testing and in general provided slower release. Drug release was found to vary with the type and level of wax, drug, excipient, and the thermal treatment. 相似文献
18.
I. E. Ribel’ 《Measurement Techniques》1969,12(8):1054-1055
Conclusions Information-theory methods should be considered as the methods of a theory for a generalized evaluation of information-transmitting
devices, whose particular case consists of measuring systems, and above all telemetering systems and those with an independent
recording of measurement results.
Translated from Izmeritel’naya Tekhnika, No. 8, pp. 14–15, August, 1969. 相似文献
19.
位于市区30多米高的孤立山包上,一座有两层内衬的53m高的砖烟囱,其中最上部有3m已出现破裂偏斜,应用烟囱定向倾倒控制爆破技术,设计迁取的合理的倾倒方向,并对最里层保温层和内衬进行了预拆除,采取了开设定向窗、烟囱外壁和中间内衬同网起爆的技术方案,共用58发瞬归电雷管,总装2号岩石硝铵炸药2475g,一次起爆成功。 相似文献
20.
材料的制备加工是决定其使用性能的重要因素之一,也是材料科学与工程的重要组成部分。近20年来,以薄板坯连铸连轧(CSP工艺)、喷射沉积、激光成形、半固态加工、复合铸造、等温成形、无模成形等为代表,材料制备加工新技术新工艺的研究开发与应用受到国内外的广泛重视,得到快速发展。由于高新技术发展对材料的使用性能的要求越来越高, 相似文献